The ``experimental`` repository can also be typically added to Ubuntu systems.
##### Upstream repository
We provide also upstream repository for ``graph-tool``. This is useful for other [Debian](http://www.debian.org/) or [Ubuntu](http://www.ubuntu.com/) releases not covered above, or if you want to install a newer version that has not yet made it into the official repository. To use it, you need to add the following line to your `/etc/apt/sources.list`,
We also provide an upstream repository for ``graph-tool``. This is useful for other [Debian](http://www.debian.org/) or [Ubuntu](http://www.ubuntu.com/) releases not covered by the official repositories, or if you want to install a newer version that has not yet made it there. New ``graph-tool`` versions are made available in the upstream repository almost immediately after release, while they can take some days to appear in the ``experimental`` Debian repository, and much longer on the other repositories. The Upstream repository is the easiest way to remain on the bleeding edge.
To use it, you need to add the following line to your `/etc/apt/sources.list`,
```
deb https://downloads.skewed.de/apt DISTRIBUTION main
