I really just wanted to add a comment to suggestions about TortoiseHG, but the comments are closed,
How to add the ppa repository on linux (replace oneiric by your version):
Add the following entries to package manager:
deb http://ppa.launchpad.net/tortoisehg-ppa/releases/ubuntu oneiric main
deb-src http://ppa.launchpad.net/tortoisehg-ppa/releases/ubuntu oneiric main
Add the following entries to package manager:
deb http://ppa.launchpad.net/mercurial-ppa/releases/ubuntu oneiric main
deb-src http://ppa.launchpad.net/mercurial-ppa/releases/ubuntu oneiric main
IMPORTANT: As current TortoiseHg versions often require a newer version of Mercurial itself than Ubuntu itself supplies, you will also need to add this PPA.
To configure APT to trust this repository's signing key, run:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key 323293EE
If you had older versions intalled, you want to remove them first.
sudo apt-get --purge remove mercurial
sudo apt-get --purge remove tortoisehg
Step
sudo apt-get install mercurial
sudo apt-get install tortoisehg