JIRA, monday.com, Redmine, Microsoft Project, TortoiseSVN, Odoo, OpenProject, Taiga.io, SourceForge, Microsoft Visual SourceSafe, YouTrack, Eventum, Perforce, Wrike, Quire, Request Tracker, Open Atrium, VisualSVN, Eclipse Mylyn, jtrac, qdPM, AnkhSVN, SuiteDash, MantisHub, icescrum, Flyspray, Issue Tracker, Portfolio for Jira, LeaderTask, web2project, Proces.io, Allegra, Project.net, voo2do, Rational ClearCase, Apache Bloodhound, MKS Source, Team Task Manager, Unified Inbox, Acunote, BugTower, Planthat, ProsperWorks, accurev, Codendi, Vermis, Stepsie, People Manager, Zoho BugTracker, Bugira, TimePanther, Atom Bug Tracker, SpectrumSCM, XBtrack task and bug tracker, Splendid Bacon, SoFreakingBoring, SourceAnywhere, tasksIT, Akiri DevBox, VisionFlow, Mana-Sys Redmine Client, Surround SCM, uberSVN, CA Agile Central, BusyFlow, RMClient are some alternatives to ZenTao.