What are some alternatives?
When comparing SourceTree and Atlassian Bitbucket Server, you can also consider the following products
GitHub Desktop - GitHub Desktop is a seamless way to contribute to projects on GitHub and GitHub Enterprise.
Visual Studio Team Services - Visual Studio Team Services (VSTS) provides unlimited Git hosting, cloud build for CI, agile planning and continuous delivery.
GitKraken - The intuitive, fast, and beautiful cross-platform Git client.
SmartGit - SmartGit is a front-end for the distributed version control system Git and runs on Windows, Mac OS...
Mercurial SCM - Mercurial is a free, distributed source control management tool.
git-cola - git-cola is a powerful GUI for git, a distributed revision control system.