Month: March 2010

After 3 years, my xmonad configuration now uses GNOME

~ Don Stewart ~ 5 Comments

Nearly three years ago, Spencer Janssen and I started work on xmonad, a tiling window manager for unix that would do what we want, automatically, so we could just concentrate on hacking code, without the window manager getting in the way. The project’s been quite successful — the most downloaded app on Hackage for the last couple of years, and thousands of users. It even has its own twitter, blog, reddit and facebook accounts.

Originally I thought of this project something as the anti-GNOME: small, learn, and every part just does one thing only, but well – in the Unix tradition. And it has stayed lean. Around two thousand lines of Haskell for the core system, but with the benefit of hundreds of extensions in the contributor’s library — everyone’s config file is potentially a library module new users can import.

Over the years, GNOME and xmonad have started playing well together to the point that there’s relatively seemless interop between the two projects: you can use the full GNOME environment, and swap in xmonad as your window manager, or use a minimal environment with xmonad, adding in GNOME tools that help you.

Playing well with others is good for your open source software.

I’ve now finally switched my xmonad configuration to use a number of gnome apps, to support the core dynamic tiling provided by xmonad. Here’s my config file:

import XMonad
import XMonad.Config.Gnome
import XMonad.Layout.NoBorders
main = xmonad
    gnomeConfig {
            terminal = "term"
          , layoutHook  = smartBorders (layoutHook gnomeConfig)
    }

Yeah, that’s it. import XMonad.Config.Gnome, add smart borders, and overide the terminal to be my urxvt wrapper. xmonad is configured in Haskell, or languages Haskell can interoperate with.

My session is started up from .xinitrc as:

gitit &
gnome-panel &
gnome-power-manager &
dbus-launch --exit-with-session xmonad

I use gitit as my personal wiki, and then put a few things in the gnome-panel.

I’m really happy with how easy it now is to use xmonad with all the regular GNOME apps that people would like to see. This kind of friendliness to the dominate tools of the day is good for the project — and good for our users.

So you want to hack Haskell for the Google Summer of Code

~ Don Stewart ~ 1 Comment

The Google Summer of Code is a great chance to work on open source projects as a student, and get training from some experience hackers, wonderfully sponsored by Google. Haskell.org will be participating for its 5th year.

If you’re thinking about working on Haskell projects, you should certainly be reading:

Here are some of the things to think about before you decide to submit a proposal to help out Haskell.org this summer, to help you make stronger proposals. This is purely my opinion, and might not necessarily reflect the opinion of all other mentors.

We have limited resources as a community, and the Google Summer of Code has been instrumental in bringing new tools and libraries to our community. Some notable projects from the past few years include:

  • The GHCi debugger
  • Improvements to Haddock
  • Major work on Cabal
  • Generalizing Parsec (parsec3)
  • Shared Libraries for GHC
  • Language.C

These student projects have gone on to have wide impact, or brought new capabilities to the Haskell community. The pattern has been towards work on the most popular tools and libraries, or work on new areas that Haskell programmers are demanding work on. Rarely do we fund development of applications in Haskell, instead concentrating on general infrastructure that supports all Haskell projects.

To succeed with your project proposal, you need to propose doing work on the most important “blockers” for Haskell’s use. Work that:

  • Brings the most value to the community
  • Addresses widespread need
  • Will impact many other libraries and tools
  • Doesn’t rewrite things in Haskell for their own sake
  • Is feasible in 3 months

It can be hard to find projects of the right size — important enough the work will make a difference — and thus attract the attention of mentors (who vote on your proposal), but is still feasible to achieve in 3 months.

To help get a sense of the mood of what the community thinks is “hot” (though not necessarily important), we set up a crowd voting site for ideas on Reddit. But be wary, the crowd can get excited about silly things, and doesn’t necessarily have good business sense.

The list of projects can help you get a sense for what Haskellers are thinking about this year. Not everything here will is feasible for a summer project though, so be sure to get advice!

Some of the social factors to consider in your application:

  • You have one or two mentors with good expertise in the area. Ideally you’re already lining up the mentors to help watch your work.
  • You’re hanging out in #haskell or on the Haskell Reddit, your blog is
    on Planet Haskell, or you’re going to be at the hackathons.

The more involved you are in the community, the more likely you’ll have a sense of what the most important work to propose is.

And of course you need to have skills to pay the bills:

  • You should have demonstrated competence in Haskell (e.g. you’ve
    uploaded things to Hackage)
  • Demonstrated discipline in open source — self-motivation

As a guide to what reviewers will be thinking about when reading your proposal, you should be able to answer (at least) the following questions from the proposal alone:

  • What are you trying to accomplish?
  • How is it done in Haskell now, and with what limitations?
  • Are there similar projects in other languages? What related work is there?
  • If successful, what difference will it make? Will it enable new Haskell business cases? Performance improvements to many libraries? Better accessibility of Hackage code?
  • What are the mid-term and final results you’re hoping to achieve?
  • How will the result of your work affect other projects?

So, now you know what we’re interested in, start writing that proposal!