Perpetual beta is the keeping of software

Computer software

Computer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it....

 or a system at the beta development stage

Development stage

A software release life cycle refers to the phases of development and maturity for a piece of computer software—ranging from its initial development, to its eventual release, and updated versions of the released version to help improve software or fix bugs still present in the software.- Pre-alpha...

 for an extended or indefinite period of time. It is often used by developers when they continue to release new features that might not be fully tested. As a result, perpetual beta software is not recommended for mission critical

Mission Critical

Mission critical refers to any factor of a system whose failure will result in the failure of business operations. That is, it is critical to the organization's 'mission'....

 machines. However, many operational systems find this to be a much more rapid and agile approach to development, staging, and deployment.

Definition

Perpetual beta has come to be associated with the development and release of a service in which constant updates are the foundation for the habitability or usability of a service. According to publisher and open source advocate Tim O'Reilly

Tim O'Reilly

Tim O'Reilly is the founder of O'Reilly Media and a supporter of the free software and open source movements.-Life and career:...

:

"Users must be treated as co-developers, in a reflection of open source development practices (even if the software in question is unlikely to be released under an open source license.) The open source dictum, 'release early and release often', in fact has morphed into an even more radical position, 'the perpetual beta', in which the product is developed in the open, with new features slipstreamed

Slipstream (computing)

In computer jargon, to slipstream updates, patches or service packs means to integrate them into the installation files of their original software, so that the resulting files will allow a direct installation of the updated software....

 in on a monthly, weekly, or even daily basis. It's no accident that services such as Gmail

Gmail

Gmail is a free, advertising-supported email service provided by Google. Users may access Gmail as secure webmail, as well via POP3 or IMAP protocols. Gmail was launched as an invitation-only beta release on April 1, 2004 and it became available to the general public on February 7, 2007, though...

, Google Maps

Google Maps

Google Maps is a web mapping service application and technology provided by Google, free , that powers many map-based services, including the Google Maps website, Google Ride Finder, Google Transit, and maps embedded on third-party websites via the Google Maps API...

, Flickr

Flickr

Flickr is an image hosting and video hosting website, web services suite, and online community that was created by Ludicorp in 2004 and acquired by Yahoo! in 2005. In addition to being a popular website for users to share and embed personal photographs, the service is widely used by bloggers to...

, del.icio.us

Del.icio.us

Delicious is a social bookmarking web service for storing, sharing, and discovering web bookmarks. The site was founded by Joshua Schachter in 2003 and acquired by Yahoo! in 2005, and by the end of 2008, the service claimed more than 5.3 million users and 180 million unique bookmarked URLs...

, and the like may be expected to bear a 'Beta' logo for years at a time."

Used in the larger conversation of what defines Web 2.0

Web 2.0

The term Web 2.0 is associated with web applications that facilitate participatory information sharing, interoperability, user-centered design, and collaboration on the World Wide Web...

, O'Reilly described the concept of perpetual beta as part of a customized Internet environment with these applications as distinguishing characteristics:

• Services, not packaged software, with cost-effective scalability
• Control over unique, hard-to-recreate data sources that get richer as more people use them
• Trusting users as co-developers
• Harnessing collective intelligence
• Leveraging the long tail
  The Long Tail
  The Long Tail or long tail refers to the statistical property that a larger share of population rests within the tail of a probability distribution than observed under a 'normal' or Gaussian distribution...
  
  through customer self-service
• Software above the level of a single device
• Lightweight user interfaces, development models, and business models.