SVN

Create a repository -
$svnadmin create ~/repo

Copy existing project files to repository
$svn import ~/project file:///home/username/repo/project

Create a sandbox project directory under version control
$svn co file:///home/repo/project
This will create a directory project in the current directory.

Commit changes
$svn ci -m "...."

Go back to the 3rd commit
$svn revert -r 3

Update local sandbox
$svn update