Fossil has the ability to import and export repositories from and to Git. And since most other version control systems will also import/export from Git, that means that you can import/export a Fossil repository to most version control systems using Git as an intermediary.

Git → Fossil

To import a Git repository into Fossil, run commands like this:

cd git-repo
git fast-export --all | fossil import new-repo.fossil

In other words, simply pipe the output of the "git fast-export" command into the "fossil import" command. The 2nd argument to the "fossil import" command is the name of a new Fossil repository that is created to hold the Git content.

Fossil → Git

To convert a Fossil repository into a Git repository, run commands like this:

git init new-repo
cd new-repo
fossil export -R ../repo.fossil | git fast-import

In other words, create a new Git repository, then pipe the output from the "fossil export" commandn into the "git fast-import" command.

Note that the "fossil export" command only exports the versioned files. Tickets and wiki and events are not exported, since Git does not understand those concepts.