MavensMate is a great plugin for the Force.com platform, built on the Sublime Text IDE. It is provided by the community (with Joe Ferraro as the creator and main contributor) as a free alternative to the well known Force.com IDE shipped by Salesforce.com.
Now, if you install the plugin on a Microsoft Windows 7 o 8 workstation, under certain conditions (usually proxy or firewalling, however not my case) you may get the following error:
Installation of Sublime Text plugin failed. This is likely due to the installer being unable to reach GitHub. If you are behind a firewall or using a proxy, you should configure git accordingly (google: git config --global https.proxy) and ensure your HTTPS/HTTPS_PROXY environment variable(s) are set properly. Otherwise, please log an issue on the MavensMate GitHub project.
There's already an issue on GitHub for this, and a useful workaround by Joe Ferraro himself.
These are the lines that worked for me:
Fire up the shell/bash and move to the MavensMate plugin directory (replace the username and root if needed)
cd "C:\Users\username\AppData\Roaming\Sublime Text 3\Packages"
Launch the following script
git clone --recursive http://github.com/joeferraro/MavensMate-SublimeText.git MavensMate
git submodule init
git submodule update
Supposedly, when you'll run Sublime Text again, MavensMate will be there.
But you're not done yet, remeber to configure the workspace through the menu MavensMate - Setting.