Gerrit
A Web based code review and project management system for Git projects
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Phabricator
Phabricator is an open source collection of development and code management, including code reviews and audits, browsing repositories, tracking bugs, etc
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Apache ZooKeeper
ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services. It is distributed and highly reliable, with Consensus, group management and presence protocols built-in.
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