Currently, Lead is only available through Git. If you have the standard Git client installed, please use this command:
git clone git://lead.git.sourceforge.net/gitroot/lead/lead
This will check out the development master branch into a new directory
lead within the current directory. Please pull regularly to update your local repository.
Note: it is strongly recommended, if not necessary, that you build the binaries yourself. The existing ones are highly outdated. See the Compile Guide for more information.
You can also browse the repository using the web interface.
For a full guide on Git usage, please read one of the many guides out there, e.g. the Git community book.