Bugzilla is a Web

World Wide Web

The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...

-based general-purpose bugtracker and testing tool

Test automation

Test automation is the use of software to control the execution of tests, the comparison of actual outcomes to predicted outcomes, the setting up of test preconditions, and other test control and test reporting functions...

 originally developed and used by the Mozilla

Mozilla

Mozilla is a term used in a number of ways in relation to the Mozilla.org project and the Mozilla Foundation, their defunct commercial predecessor Netscape Communications Corporation, and their related application software....

 project, and licensed under the Mozilla Public License

Mozilla Public License

The Mozilla Public License is a free and open source software license. Version 1.0 was developed by Mitchell Baker when she worked as a lawyer at Netscape Communications Corporation and version 1.1 at the Mozilla Foundation...

.

Released as open source software by Netscape Communications in 1998, it has been adopted by a variety of organizations for use as a bug tracking system

Bug tracking system

A bug tracking system is a software application that is designed to help quality assurance and programmers keep track of reported software bugs in their work. It may be regarded as a type of issue tracking system....

 for both free and open source software

Free and open source software

Free and open-source software or free/libre/open-source software is software that is liberally licensed to grant users the right to use, study, change, and improve its design through the availability of its source code...

 and proprietary

Proprietary software

Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...

 projects and products.
Bugzilla was originally written by Terry Weissman in 1998 for the nascent Mozilla.org project, as an open source

Open source

The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

 application to replace the in-house system then in use at Netscape Communications for tracking defects in the Netscape Communicator

Netscape Communicator

Netscape Communicator was an Internet suite produced by Netscape Communications Corporation. Initially released in June 1997, Netscape Communicator 4.0 was the successor to Netscape Navigator 3.x and included more groupware features intended to appeal to enterprises.- Editions :Netscape...

 suite.