A voting system or electoral system is a method by which voters make a choice between options, often in an election or on a policy referendum....
developed in 1997 by Markus Schulze that selects a single winner using votes that express preferences
Preferential voting
Preferential voting is a type of ballot structure used in several electoral systems in which voters rank candidates in order of relative preference. For example, the voter may select their first choice as '1', their second preference a '2', and so on...
. The method can also be used to create a sorted list of winners. The Schulze method is also known as Schwartz Sequential Dropping (SSD), Cloneproof Schwartz Sequential Dropping (CSSD), the Beatpath Method, Beatpath Winner, Path Voting, and Path Winner.
A Condorcet method is any single-winner election method that meets the Condorcet criterion, which means the method always selects the Condorcet winner if such a candidate exists. The Condorcet winner is the candidate who would beat each of the other candidates in a run-off election.In modern...
, which means the following: if there is a candidate who is preferred over every other candidate in pairwise comparisons, then this candidate will be the winner when the Schulze method is applied.
Currently, the Schulze method is the most widespread Condorcet method (list). The Schulze method is used by several organizations including Wikimedia
Wikimedia Foundation
Wikimedia Foundation, Inc. is an American non-profit charitable organization headquartered in San Francisco, California, United States, and organized under the laws of the state of Florida, where it was initially based...
Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...
Gentoo Linux is a computer operating system built on top of the Linux kernel and based on the Portage package management system. It is distributed as free and open source software. Unlike a conventional software distribution, the user compiles the source code locally according to their chosen...
Software in the Public Interest, Inc. is a non-profit organization formed to help other organizations create and distribute free/open-source software and open-source hardware...
.
The output of the Schulze method (defined below) gives an ordering of candidates. Therefore, if several positions are available, the method can be used for this purpose without modification, by letting the k top-ranked candidates win the k available seats. Furthermore, for proportional representation
Proportional representation
Proportional representation is a concept in voting systems used to elect an assembly or council. PR means that the number of seats won by a party or group of candidates is proportionate to the number of votes received. For example, under a PR voting system if 30% of voters support a particular...
Schulze STV is a draft preference voting system designed to achieve proportional representation. It was invented by Markus Schulze who developed the Schulze method for resolving ties under the Condorcet method. It is similar to CPO-STV in that it compares possible winning sets of candidate...
has been proposed.
Ballot
The input to the Schulze method is the same as for other preferential
Preferential voting
Preferential voting is a type of ballot structure used in several electoral systems in which voters rank candidates in order of relative preference. For example, the voter may select their first choice as '1', their second preference a '2', and so on...
In set theory, a total order, linear order, simple order, or ordering is a binary relation on some set X. The relation is transitive, antisymmetric, and total...
To tie or draw is to finish a competition with identical or inconclusive results. The word "tie" is usually used in North America for sports such as American football. "Draw" is usually used in the United Kingdom, Ireland and the Commonwealth of Nations and it is usually used for sports such as...
are allowed.
One typical way for voters to specify their preferences on a ballot (see left) is as follows. Each ballot lists all the candidates, and each voter ranks this list in order of preference using numbers: the voter places a '1' beside the most preferred candidate(s), a '2' beside the second-most preferred, and so forth. Each voter may optionally:
give the same preference to more than one candidate. This indicates that this voter is indifferent between these candidates.
use non-consecutive numbers to express preferences. This has no impact on the result of the elections, since only the order in which the candidates are ranked by the voter matters, and not the absolute numbers of the preferences.
keep candidates unranked. When a voter doesn't rank all candidates, then this is interpreted as if this voter (i) strictly prefers all ranked to all unranked candidates, and (ii) is indifferent among all unranked candidates.
Schulze Method
Let d[V,W] be the number of voters who prefer candidate V to candidate W.
A path from candidate X to candidate Y of strength p is a sequence
Sequence
In mathematics, a sequence is an ordered list of objects . Like a set, it contains members , and the number of terms is called the length of the sequence. Unlike a set, order matters, and exactly the same elements can appear multiple times at different positions in the sequence...
of candidates C(1),...,C(n) with the following properties:
C(1) = X and C(n) = Y.
For all i = 1,...,(n-1): d[C(i),C(i+1)] > d[C(i+1),C(i)].
For all i = 1,...,(n-1): d[C(i),C(i+1)] ≥ p.
p[A,B], the strength of the strongest path from candidate A to candidate B, is the maximum value such that there is a path from candidate A to candidate B of that strength. If there is no path from candidate A to candidate B at all, then p[A,B] = 0.
Candidate D is better than candidate E if and only if p[D,E] > p[E,D].
Candidate D is a potential winner if and only if p[D,E] ≥ p[E,D] for every other candidate E.
It can be proven that p[X,Y] > p[Y,X] and p[Y,Z] > p[Z,Y] together imply p[X,Z] > p[Z,X]. Therefore, it is guaranteed (1) that the above definition of "better" really defines a transitive relation
Transitive relation
In mathematics, a binary relation R over a set X is transitive if whenever an element a is related to an element b, and b is in turn related to an element c, then a is also related to c....
and (2) that there is always at least one candidate D with p[D,E] ≥ p[E,D] for every other candidate E.
Example
Consider the following example, in which 45 voters rank 5 candidates.
5 ACBED (meaning, 5 voters have order of preference: A > C > B > E > D)
5 ADECB
8 BEDAC
3 CABED
7 CAEBD
2 CBADE
7 DCEBA
8 EBADC
First, we compute the pairwise preferences. For example, in comparing A and B pairwise, there are 5+5+3+7=20 voters who prefer A to B, and 8+2+7+8=25 voters who prefer B to A. So d[A, B] = 20 and d[B, A] = 25. The full set of pairwise preferences is:
Matrix of pairwise preferences
d[*,A]
d[*,B]
d[*,C]
d[*,D]
d[*,E]
d[A,*]
20
26
30
22
d[B,*]
25
16
33
18
d[C,*]
19
29
17
24
d[D,*]
15
12
28
14
d[E,*]
23
27
21
31
To help visualize the strongest paths, the diagram on the right-hand side shows an arrow from A to B with label d[A, B], in the style of a directed graph
Directed graph
A directed graph or digraph is a pair G= of:* a set V, whose elements are called vertices or nodes,...
. (To avoid cluttering the diagram we only draw the majority of voters)
Recall that the strength of a path is the strength of its weakest link. One example of computing the strongest path strength is p[B, D] = 33: the strongest path from B to D is the direct path (B, D) which has strength 33. For contrast, let us also compute p[A, C]. The strongest path from A to C is not the direct path (A, C) of strength 26, rather the strongest path is the indirect path (A, D, C) which has strength min(30, 28) = 28.
For each pair of candidates X and Y, the following table shows the strongest path from candidate X to candidate Y in red, with the weakest link underlined.
Strongest paths
... to A
... to B
... to C
... to D
... to E
from A ...
A-(30)-D-(28)-C-(29)-B
A-(30)-D-(28)-C
A-(30)-D
A-(30)-D-(28)-C-(24)-E
from A ...
from B ...
B-(25)-A
B-(33)-D-(28)-C
B-(33)-D
B-(33)-D-(28)-C-(24)-E
from B ...
from C ...
C-(29)-B-(25)-A
C-(29)-B
C-(29)-B-(33)-D
C-(24)-E
from C ...
from D ...
D-(28)-C-(29)-B-(25)-A
D-(28)-C-(29)-B
D-(28)-C
D-(28)-C-(24)-E
from D ...
from E ...
E-(31)-D-(28)-C-(29)-B-(25)-A
E-(31)-D-(28)-C-(29)-B
E-(31)-D-(28)-C
E-(31)-D
from E ...
... to A
... to B
... to C
... to D
... to E
Strengths of the strongest paths
p[*,A]
p[*,B]
p[*,C]
p[*,D]
p[*,E]
p[A,*]
28
28
30
24
p[B,*]
25
28
33
24
p[C,*]
25
29
29
24
p[D,*]
25
28
28
24
p[E,*]
25
28
28
31
Now we can determine the output of the Schulze method. Comparing A and B for example,
since 28 = p[A,B] > p[B,A] = 25, for the Schulze method candidate A is better than candidate B. Another example is that 31 = p[E,D] > p[D,E] = 24, so candidate E is better than candidate D. Continuing in this way we get the Schulze ranking is E > A > C > B > D, and E wins. In other words, E wins since p[E,X] ≥ p[X,E] for every other candidate X.
Implementation
The only difficult step in implementing the Schulze method is computing the strongest path strengths. However, this is a well-known problem in graph theory sometimes called the widest path problem
Widest path problem
In graph algorithms, the widest path problem, also known as the bottleneck shortest path problem or the maximum capacity path problem, is the problem of finding a path between two designated vertices in a weighted directed graph, maximizing the weight of the minimum-weight edge in the path.For...
. One simple way to compute the strengths therefore is a variant of the Floyd–Warshall algorithm. The following pseudocode
Pseudocode
In computer science and numerical computation, pseudocode is a compact and informal high-level description of the operating principle of a computer program or other algorithm. It uses the structural conventions of a programming language, but is intended for human reading rather than machine reading...
illustrates the algorithm.
Input: d[i,j], the number of voters who prefer candidate i to candidate j.
Output: p[i,j], the strength of the strongest path from candidate i to candidate j.
for i from 1 to C
for j from 1 to C
if (i ≠ j) then
if (d[i,j] > d[j,i]) then
p[i,j] := d[i,j]
else
p[i,j] := 0
for i from 1 to C
for j from 1 to C
if (i ≠ j) then
for k from 1 to C
if (i ≠ k and j ≠ k) then
p[j,k] := max ( p[j,k], min ( p[j,i], p[i,k] ) )
This algorithm is efficient, and has running time proportional to C3 where C is the number of candidates. (This does not account for the running time of computing the d[*,*] values, which if implemented in the most straightforward way, takes time proportional to C2 times the number of voters.)
Ties and alternative implementations
When we allow users to have ties in their preferences, the outcome of the Schulze method naturally depends on how we interpret these ties in defining d[*,*]. Two natural choices are that d[A, B] represents either the number of voters who strictly prefer A to B (A>B), or the margin of (voters with A>B) minus (voters with B>A). But no matter how the ds are defined, the Schulze ranking has no cycles, and assuming the ds are unique it has no ties.
Although ties in the Schulze ranking are unlikely, they are possible. Schulze's original paper proposed breaking ties in accordance with a voter selected at random, and iterating as needed.
An alternative, slower, way to describe the winner of the Schulze method is the following procedure:
A directed graph or digraph is a pair G= of:* a set V, whose elements are called vertices or nodes,...
with all candidates, and all possible edges between candidates
iteratively [a] delete all candidates not in the Schwartz set
Schwartz set
In voting systems, the Schwartz set is the union of all Schwartz set components. A Schwartz set component is any non-empty set S of candidates such that...
(i.e. any candidate which cannot reach all others) and [b] delete the weakest link
the winner is the last non-deleted candidate.
Satisfied criteria
The Schulze method satisfies the following criteria:
In social choice theory, unrestricted domain, or universality, is a property of social welfare functions in which all preferences of all voters are allowed...
In social choice theory, Arrow’s impossibility theorem, the General Possibility Theorem, or Arrow’s paradox, states that, when voters have three or more distinct alternatives , no voting system can convert the ranked preferences of individuals into a community-wide ranking while also meeting a...
In social choice theory, Arrow’s impossibility theorem, the General Possibility Theorem, or Arrow’s paradox, states that, when voters have three or more distinct alternatives , no voting system can convert the ranked preferences of individuals into a community-wide ranking while also meeting a...
In voting theory, non-dictatorship is a property of social choice functions, where the results cannot simply mirror that of any ONE single person's preferences without consideration of the other voters. Fairness requires that the social welfare function take into account the desires of more than...
Pareto efficiency, or Pareto optimality, is a concept in economics with applications in engineering and social sciences. The term is named after Vilfredo Pareto, an Italian economist who used the concept in his studies of economic efficiency and income distribution.Given an initial allocation of...
The monotonicity criterion is a voting system criterion used to analyze both single and multiple winner voting systems. A voting system is monotonic if it satisfies one of the definitions of the monotonicity criterion, given below.Douglas R...
The majority criterion is a single-winner voting system criterion, used to compare such systems. The criterion states that "if one candidate is preferred by a majority of voters, then that candidate must win"....
The majority loser criterion is a criterion to evaluate single-winner voting systems. The criterion states that if a majority of voters prefers every other candidate over a given candidate, then that candidate must not win....
The Condorcet candidate or Condorcet winner of an election is the candidate who, when compared with every other candidate, is preferred by more voters. Informally, the Condorcet winner is the person who would win a two-candidate election against each of the other candidates...
In single-winner voting system theory, the Condorcet loser criterion is a measure for differentiating voting systems. It implies the majority loser criterion....
In voting systems, the Schwartz set is the union of all Schwartz set components. A Schwartz set component is any non-empty set S of candidates such that...
The Smith criterion is a voting systems criterion defined such that its satisfaction by a voting system occurs when the system always picks the winner from the Smith set, the smallest set of candidates such that every member of the set is pairwise preferred to every candidate not in the set...
The mutual majority criterion is a criterion used to compare voting systems. It is also known as the majority criterion for solid coalitions and the generalized majority criterion...
In voting systems theory, the independence of clones criterion measures an election method's robustness to strategic nomination. Nicolaus Tideman first formulated the criterion, which states that the addition of a candidate identical to one already present in an election will not cause the winner...
Reversal symmetry is a voting system criterion which requires that if candidate A is the unique winner, and each voter's individual preferences are inverted, then A must not be elected. Methods that satisfy reversal symmetry include Borda count, the Kemeny-Young method, and the Schulze method...
Resolvability criterion can refer to any voting system criterion that ensures a low possibility of tie votes.#Nicolaus Tideman's version of the criterion demands that if and only if for every winner in a result, a vote exists, such that when added, makes that winner unique.#Douglas R...
Plurality criterion is a voting system criterion devised by Douglas R. Woodall for ranked voting methods with incomplete ballots. It is stated as follows:...
if winning votes are used for d[X,Y]
Symmetric-completion if margins are used for d[X,Y]
The Condorcet candidate or Condorcet winner of an election is the candidate who, when compared with every other candidate, is preferred by more voters. Informally, the Condorcet winner is the person who would win a two-candidate election against each of the other candidates...
The participation criterion is a voting system criterion. It is also known as the "no show paradox". It has been defined as follows:* In a deterministic framework, the participation criterion says that the addition of a ballot, where candidate A is strictly preferred to candidate B, to an existing...
A voting system is consistent if, when the electorate is divided arbitrarily into two parts and separate elections in each part result in the same choice being selected, an election of the entire electorate also selects that alternative...
In voting systems, tactical voting occurs, in elections with more than two viable candidates, when a voter supports a candidate other than his or her sincere preference in order to prevent an undesirable outcome.It has been shown by the Gibbard-Satterthwaite theorem that any voting method which is...
In voting systems, tactical voting occurs, in elections with more than two viable candidates, when a voter supports a candidate other than his or her sincere preference in order to prevent an undesirable outcome.It has been shown by the Gibbard-Satterthwaite theorem that any voting method which is...
The later-no-harm criterion is a voting system criterion formulated by Douglas Woodall. The criterion is satisfied if, in any election, a voter giving an additional ranking or positive rating to a less preferred candidate cannot cause a more preferred candidate to lose.- Complying methods :Single...
Likewise, since the Schulze method is not a dictatorship and agrees with unanimous votes, Arrow's Theorem implies it fails the criterion
Independence of irrelevant alternatives is an axiom of decision theory and various social sciences.The word is used in different meanings in different contexts....
Comparison table
The following table compares the Schulze method with other preferential
Preferential voting
Preferential voting is a type of ballot structure used in several electoral systems in which voters rank candidates in order of relative preference. For example, the voter may select their first choice as '1', their second preference a '2', and so on...
The monotonicity criterion is a voting system criterion used to analyze both single and multiple winner voting systems. A voting system is monotonic if it satisfies one of the definitions of the monotonicity criterion, given below.Douglas R...
The Condorcet candidate or Condorcet winner of an election is the candidate who, when compared with every other candidate, is preferred by more voters. Informally, the Condorcet winner is the person who would win a two-candidate election against each of the other candidates...
The majority criterion is a single-winner voting system criterion, used to compare such systems. The criterion states that "if one candidate is preferred by a majority of voters, then that candidate must win"....
In single-winner voting system theory, the Condorcet loser criterion is a measure for differentiating voting systems. It implies the majority loser criterion....
The majority loser criterion is a criterion to evaluate single-winner voting systems. The criterion states that if a majority of voters prefers every other candidate over a given candidate, then that candidate must not win....
The mutual majority criterion is a criterion used to compare voting systems. It is also known as the majority criterion for solid coalitions and the generalized majority criterion...
The Smith criterion is a voting systems criterion defined such that its satisfaction by a voting system occurs when the system always picks the winner from the Smith set, the smallest set of candidates such that every member of the set is pairwise preferred to every candidate not in the set...
In voting systems theory, the independence of clones criterion measures an election method's robustness to strategic nomination. Nicolaus Tideman first formulated the criterion, which states that the addition of a candidate identical to one already present in an election will not cause the winner...
Reversal symmetry is a voting system criterion which requires that if candidate A is the unique winner, and each voter's individual preferences are inverted, then A must not be elected. Methods that satisfy reversal symmetry include Borda count, the Kemeny-Young method, and the Schulze method...
The participation criterion is a voting system criterion. It is also known as the "no show paradox". It has been defined as follows:* In a deterministic framework, the participation criterion says that the addition of a ballot, where candidate A is strictly preferred to candidate B, to an existing...
A voting system is consistent if, when the electorate is divided arbitrarily into two parts and separate elections in each part result in the same choice being selected, an election of the entire electorate also selects that alternative...
Ranked pairs or the Tideman method is a voting system developed in 1987 by Nicolaus Tideman that selects a single winner using votes that express preferences. RP can also be used to create a sorted list of winners....
The Borda count can be combined with an Instant Runoff procedure to create hybrid election methods that are called Nanson method and Baldwin method.- Nanson method :The Nanson method is based on the original work of the mathematician Edward J...
Instant-runoff voting , also known as preferential voting, the alternative vote and ranked choice voting, is a voting system used to elect one winner. Voters rank candidates in order of preference, and their ballots are counted as one vote for their first choice candidate. If a candidate secures a...
The Borda count is a single-winner election method in which voters rank candidates in order of preference. The Borda count determines the winner of an election by giving each candidate a certain number of points corresponding to the position in which he or she is ranked by each voter. Once all...
Bucklin voting is a class of voting systems that can be used for single-member and multi-member districts. It is named after its original promoter, James W. Bucklin of Grand Junction, Colorado, and is also known as the Grand Junction system...
The Coombs' method is a voting system created by Clyde Coombs used for single-winner elections in which each voter rank the candidates in order of preference. It is very similar to instant-runoff voting , a more common preferential voting system.-Procedures:Each voter rank-orders all of the...
In voting systems, the Minimax method is one of several Condorcet methods used for tabulating votes and determining a winner when using preferential voting in a single-winner election...
The plurality voting system is a single-winner voting system often used to elect executive officers or to elect members of a legislative assembly which is based on single-member constituencies...
Anti-plurality voting describes a voting method in which each voter votes against a single candidate, and the candidate with the fewest votes against wins. Anti-plurality voting is an example of a positional voting method.- An Example :...
The contingent vote is an electoral system used to elect a single winner, in which the voter ranks the candidates in order of preference. In an election, if no candidate receives an absolute majority of first preference votes, then all but the two leading candidates are eliminated and there is a...
Dodgson's Method is a voting system proposed by Charles Dodgson.-Description:In Dodgson's method, each voter submits an ordered list of all candidates according to their own preference . The winner is defined to be the candidate for whom we need to perform the minimum number of pairwise swaps ...
The main difference between the Schulze method and the ranked pairs
Ranked Pairs
Ranked pairs or the Tideman method is a voting system developed in 1987 by Nicolaus Tideman that selects a single winner using votes that express preferences. RP can also be used to create a sorted list of winners....
method (both of which have tick the same boxes in the above table) can be seen in this example:
Suppose the MinMax score of a set X of candidates is the strength of the strongest pairwise win of a candidate A ∉ X against a candidate B ∈ X. Then the Schulze method, but not the ranked pairs
Ranked Pairs
Ranked pairs or the Tideman method is a voting system developed in 1987 by Nicolaus Tideman that selects a single winner using votes that express preferences. RP can also be used to create a sorted list of winners....
method, guarantees that the winner is always a candidate of the set with minimum MinMax score. So, in some sense, the Schulze method minimizes the strongest pairwise win that has to be overturned when determining the winner.
History of the Schulze method
The Schulze method was developed by Markus Schulze in 1997. It was first discussed in public mailing lists in 1997–1998 and in 2000. Subsequently, Schulze method users included Software in the Public Interest
Software in the Public Interest
Software in the Public Interest, Inc. is a non-profit organization formed to help other organizations create and distribute free/open-source software and open-source hardware...
Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...
Gentoo Linux is a computer operating system built on top of the Linux kernel and based on the Portage package management system. It is distributed as free and open source software. Unlike a conventional software distribution, the user compiles the source code locally according to their chosen...
TopCoder is a company which administers contests in computer programming. TopCoder hosts fortnightly online algorithm competitions — known as SRMs or "single round matches" — as well as weekly competitions in design and development. The work in design and development produces useful software...
Wikimedia Foundation, Inc. is an American non-profit charitable organization headquartered in San Francisco, California, United States, and organized under the laws of the state of Florida, where it was initially based...
KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...
The Free Software Foundation Europe was founded in 2001 as an official European sister organization of the U.S.-based Free Software Foundation to take care of all aspects of free software in Europe. FSF and FSFE are financially and legally separate entities.FSFE believes that access to and...
(2008), the Pirate Party of Sweden (2009), and the Pirate Party of Germany (2010). In the French Wikipedia, the Schulze method was one of two multi-candidate methods approved by a majority in 2005, and it has been used several times.
In 2011, Schulze published the method in the academic journal Social Choice and Welfare.
Use of the Schulze method
The Schulze method is not currently used in parliamentary elections. However, it has been used for parliamentary primaries in the Swedish Pirate Party. It is also starting to receive support in other public organizations. Organizations which currently use the Schulze method are:
Annodex is a digital media format developed by CSIRO to provide annotation and indexing of continuous media, such as audio and video.It is based on the Ogg container format, with an XML language called CMML providing additional metadata...
BoardGameGeek is a website that was founded in January 2000 by Scott Alden and Derk Solko as a resource for the board gaming hobby. The database holds reviews, articles, and session reports for over 45,000 different games, expansions, and designers. BoardGameGeek includes German-style board games,...
The University of South Florida, also known as USF, is a member institution of the State University System of Florida, one of the state's three flagship universities for public research, and is located in Tampa, Florida, USA...
The University of York , is an academic institution located in the city of York, England. Established in 1963, the campus university has expanded to more than thirty departments and centres, covering a wide range of subjects...
Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...
EuroBillTracker is a website designed for tracking euro banknotes. It was inspired by the U.S. currency tracking website Where's George?.- Characteristics :...
The European Democratic Education Conference is a biennial conference of the European Democratic Education Community, a European network of people involved in democratic education. The first conference was held in Leipzig, Germany, from July 25 to August 3, 2008...
FFmpeg is a free software project that produces libraries and programs for handling multimedia data. The most notable parts of FFmpeg are libavcodec, an audio/video codec library used by several other projects, libavformat, an audio/video container mux and demux library, and the ffmpeg command line...
Free Geek is a collectively run non-profit organization started in Portland, Oregon in 2000. Free Geek has two central goals: to reuse or recycle used computer equipment that might otherwise become hazardous waste, and to make computer technology more accessible to those who lack financial means or...
The Free Software Foundation Europe was founded in 2001 as an official European sister organization of the U.S.-based Free Software Foundation to take care of all aspects of free software in Europe. FSF and FSFE are financially and legally separate entities.FSFE believes that access to and...
Gentoo Linux is a computer operating system built on top of the Linux kernel and based on the Portage package management system. It is distributed as free and open source software. Unlike a conventional software distribution, the user compiles the source code locally according to their chosen...
GNU Privacy Guard is a GPL Licensed alternative to the PGP suite of cryptographic software. GnuPG is compliant with RFC 4880, which is the current IETF standards track specification of OpenPGP...
Haskell is a standardized, general-purpose purely functional programming language, with non-strict semantics and strong static typing. It is named after logician Haskell Curry. In Haskell, "a function is a first-class citizen" of the programming language. As a functional programming language, the...
KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...
The John S. and James L. Knight Foundation is an American private, non-profit foundation dedicated to supporting transformational ideas that promote quality journalism, advance media innovation, engage communities and foster the arts....
Kumoricon is an annual three-day anime convention held in the Portland, Oregon metro area. Kumori means cloudy weather in Japanese. Cosplaying attendees have ranged from Jack Skellington to Pac-Man, filling the area with "ninjas, giant bugs, girls with cat ears, and guys in the uniforms of...
The League of Professional System Administrators is a non-profit organization. The organization's mission is "to advance the practice of system administration; to support, recognize, educate, and encourage its practitioners; and to serve the public through education and outreach on system...
Cinelerra is prosumer video editing software. It is designed for the GNU/Linux operating system. It is produced by Heroine Virtual, and is free software distributed under the GNU General Public License...
The Metalab is a hackerspace in Vienna's central first district.Founded in 2006, it is a meeting place of the Viennese tech community, hosting events from culture festivals to user groups....
MTV, formerly an initialism of Music Television, is an American network based in New York City that launched on August 1, 1981. The original purpose of the channel was to play music videos guided by on-air hosts known as VJs....
netznetz is a social platform for individuals and groups associated with net art and net culture in Vienna, Austria. The platform was dissolved around 2011 because of internal problems and loss of funding from the Viennese city....
Noisebridge is an award winning anarchistic educational hackerspace in San Francisco, inspired by the Chaos Computer Club and other hacker organizations. It is a registered non-profit California corporation, with IRS 501 charitable status...
OpenEmbedded is a software framework to create Linux distributions aimed for, but not restricted to, embedded devices. The build system is based on BitBake recipes, which behave similar to Gentoo's ebuilds....
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Pirate Party Australia is an informal and currently unregistered political party in Australia that represents civil liberty issues. The party is based on the Swedish Pirate Party and is focused on copyright reform, internet freedom, and ending censorship...
The Pirate Party of Austria is the Austrian section of the Pirate Parties International movement which fights for freedom of information and the protection of privacy....
The Pirate party of Brazil is a political party in Brazil. Based on the model of the Swedish Pirate Party, it supports reform of copyright law, freedom of information, and privacy. The party was a founding member of Pirate Parties International....
The French Pirate Party is a political party based on the model of the Swedish Piratpartiet.The party proposes the reform of the copyright law, free access to scientific knowledge, as well as protection of individual freedom. Like other pirate parties worldwide it is affiliated to Pirate Parties...
The Pirate Party of New Zealand is a political party in New Zealand. The party is based on the Swedish Pirate Party and focuses on issues of copyright and patent reform and internet privacy...
Sender Policy Framework is an email validation system designed to prevent email spam by detecting email spoofing, a common vulnerability, by verifying sender IP addresses. SPF allows administrators to specify which hosts are allowed to send mail from a given domain by creating a specific SPF...
Software in the Public Interest, Inc. is a non-profit organization formed to help other organizations create and distribute free/open-source software and open-source hardware...
The Squeak programming language is a Smalltalk implementation. It is object-oriented, class-based and reflective.It was derived directly from Smalltalk-80 by a group at Apple Computer that included some of the original Smalltalk-80 developers...
Sugar Labs is a software-development and learning community.Sugar Labs is a non-profit foundation whose mission is to produce, distribute, and support the use of the Sugar learning platform. Sugar Labs supports the community of educators and software developers who want to extend the platform and...
TopCoder is a company which administers contests in computer programming. TopCoder hosts fortnightly online algorithm competitions — known as SRMs or "single round matches" — as well as weekly competitions in design and development. The work in design and development produces useful software...
Wikimedia Foundation, Inc. is an American non-profit charitable organization headquartered in San Francisco, California, United States, and organized under the laws of the state of Florida, where it was initially based...
Wikipedia is a free, web-based, collaborative, multilingual encyclopedia project supported by the non-profit Wikimedia Foundation. Its 20 million articles have been written collaboratively by volunteers around the world. Almost all of its articles can be edited by anyone with access to the site,...
The French Wikipedia is the French language edition of Wikipedia, spelt Wikipédia. This edition was started in March 2001, and has about articles as of , making it the third-largest Wikipedia overall, after the English-language and German-language editions...
Hebrew Wikipedia is the Hebrew edition of Wikipedia. This edition began in July 2003 and has about articles as of .-Milestones:* July 8, 2003: The Hebrew edition of Wikipedia was launched....
The Hungarian Wikipedia is the Hungarian/Magyar version of Wikipedia, the free encyclopedia. Started on July 8, 2003, this version reached the 200,000 article milestone in September 2011.-History:...
The Russian Wikipedia is the Russian language edition of Wikipedia. It has over articles. It was founded on 20 May 2001. By May 2008 it became the 10th largest Wikipedia by size and in February 2011 it ranked 8th. It surpassed 750,000 articles in August 2011...
Bernhard Nebel, born 1956, is a German Artificial Intelligence scientist. He is a full professor at the Albert-Ludwigs-Universität Freiburg where he holds the chair for foundations of Artificial Intelligence....
T. Nicolaus Tideman is a Professor of Economics at Virginia Polytechnic Institute and State University. He received his Bachelor of Arts in economics and mathematics from Reed College in 1965 and his PhD in economics from the University of Chicago in 1969...
Benjamin Mako Hill is a Debian hacker, intellectual property researcher, activist and author. He is a contributor and free software developer as part of the Debian and Ubuntu projects as well as the author of two best-selling technical books on the subject, Debian GNU/Linux 3.1 Bible and The...
The input to the Schulze method is the same as for other preferential
The Schulze method is not currently used in parliamentary elections. However, it has been used for parliamentary primaries in the Swedish Pirate Party. It is also starting to receive support in other public organizations. Organizations which currently use the Schulze method are:
