1. Cvs. http://cvs.nongnu.org/. Accessed February 27 2014. Cvs. http://cvs.nongnu.org/. Accessed February 27 2014.
2. Git. http://git-scm.com/. Accessed February 27 2014. Git. http://git-scm.com/. Accessed February 27 2014.
3. gitective: Git repository analysis tool. https://github.com/kevinsawicki/gitective. Accessed September 6 2013. gitective: Git repository analysis tool. https://github.com/kevinsawicki/gitective. Accessed September 6 2013.
4. Github. http://www.github.com/. Accessed February 27 2014. Github. http://www.github.com/. Accessed February 27 2014.
5. Mercurial. Accessed February 27 2014. Mercurial. Accessed February 27 2014.