Fossil is the coolest distributed SCM you are not using. No seriously. It boasts features not found in any of the common distributed SCMs used by nearly every developer today.
About 5 or 6 years ago I started getting a little frustrated with Git. The main complaint I kept coming back to over and over was, to use Git effectively, one needed to use GitHub, Trac, or any other ways to add an interface with issues and information. There was also the problem of getting many CVS/SVN folks comfortable with Git terminology which fueled my recommendation of Mercurial, but I digress. It was around this time that a friend of mine and I started looking at a way we could include issues within a Git repository. At that time we looked a projects like BugsEverywhere which provide a separate tool to track bugs within the repository. We gave it a go for a little while but eventually fell away from it as, at the time, it really felt like a second class citizen in the Git toolchain. We spent a little time developing our on solution but then gave up realizing that Git was so tied to the GitHub way.
Around this time one of us found Fossil and started to play around with it. I was blown away at how it took care of code, issues, wiki, tracking, and code hosting. You essentially get a distributed version of Trac for every clone. All the data comes along and you are able to update documentation, code, issues, etc.. all as part of a fossil push.
As of the time of writing Fossil boasts (from the main page):
- Integrated Bug Tracking, Wiki, and Technotes
- Built-In Web Interface
- Self-Contained
- Simple Networking
- CGI/SCGI Enabled
- Autosync
- Robust & Reliable
- Free and Open-Source
I touched a little bit on 1 and 2, but 3 is also a pretty cool feature. If you do an install of Git you really are installing a bit more than you may realize. For example, Fedora’s Git package requires:
- asciidoc
- desktop-file-utils
- emacs
- expat-devel
- gettext
- libcurl-devel
- libgnome-keyring-devel
- openssl-devel
- pcre-devel
- perl(Error)
- perl(ExtUtils::MakeMaker)
- pkgconfig(bash-completion)
- python
- rpmlib(CompressedFileNames) <= 3.0.4-1
- rpmlib(FileDigests) <= 4.6.0-1
- systemd
- xmlto
- zlib-devel >= 1.2
In other words you need a specific editor, 2 languages available on the system, a specific init system, and a part of GNOME. Plain Git directly from source requires less, but still more than one would think. Fossil notes it’s dependencies as:
Fossil needs to be linked against zlib. If the HTTPS option is enabled, then it will also need to link against the appropriate SSL implementation. And, of course, Fossil needs to link against the standard C library. No other libraries or external dependences are used.
Philosophy
Fossil and Git have very different philosophies. The most interesting point to me when reading up on the differences was this:
Git puts a lot of emphasis on maintaining a “clean” check-in history. Extraneous and experimental branches by individual developers often never make it into the main repository. And branches are often rebased before being pushed, to make it appear as if development had been linear. Git strives to record what the development of a project should have looked like had there been no mistakes.
Fossil, in contrast, puts more emphasis on recording exactly what happened, including all of the messy errors, dead-ends, experimental branches, and so forth. One might argue that this makes the history of a Fossil project “messy”. But another point of view is that this makes the history “accurate”. In actual practice, the superior reporting tools available in Fossil mean that the added “mess” is not a factor.
One commentator has mused that Git records history according to the victors, whereas Fossil records history as it actually happened.
While pretty, (nearly) liner history is a simple read it rarely is actually true.
Using Fossil
There is a pretty decent quick start to get one started. At first run through it feels clunky. For instance, when doing a checkout you have to open the repository with fossil open but then again people felt (and some still feel) that git add $FILES, git commit, git push $PLACE $BRANCH feels wrong. I think that with enough time one can be just as comfortable with fossil’s commands and flow as they would be with git.
Truth Be Told
My biggest want for Fossil to take off is to be able to offline and merge bugs/issues and documentation without forcing everyone to adopt third party tools to integrate with an SCM. I also would like to keep my hands on my keyboard rather than logging into GitHub to review stuff (yeah, I know there are keyboard shortcuts …). Anyway, here is hoping more people will give Fossil a try!
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