My network configuration doesn’t allow the computer to run as a server, so Subversion and others are out. Github offers non-public version controlling only for paying customers.
Anybody knows a solution where a few developers can work on the same code, for free, without sharing it with the whole world. Even merging directories between pendrives would do, if such software exists.
BitBucket does private repositories for up to 5 developers. BitBucket does Git or Mercurial, take your pick.