Some distributions (e.g. Arch Linux) have decided to make the "python" command run Python 3 by default. This is a problem for us, because Python 3 is not compatible with Python 2. Most Python ROX applications start like this (e.g. Edit/AppRun):

#!/usr/bin/env python

On Arch Linux, these programs will now fail to start. We can't change the line to run "python2", because that doesn't exist on other systems (e.g. Debian).

To solve this, I've added a 0install feed for Python. If your feed currently looks like this:

Normally, a ROX AppDir is a read-only directory containing program code. This makes it easy to manage programs using the filer. However, it's hard to manage configuration, which goes in various hidden files (hopefully under ~/.config).

With 0install, the program's code goes in a shared cache instead, allowing it to be shared automatically, and leaving the application directory almost empty.

This opens up the possibility of reusing the appdir for configuration. Instead of making it easy to manage code with the filer, this makes it easy to manage configurations.

In 2007, OSNews ran an article about OPIUM, showing how to cast apt-get installation problems (choosing which of several possible dependencies to install) as a set of pseudo-boolean constraints which could then be solved mathematically to give the optimal solution. I this post, I'll describe how we've recently adapted this technique to Zero Install, addressing some problems experienced by the Sugar environment (One Laptop Per Child) and allowing better integration with distribution packages.

Si vous venez d'installer ROX, ou pensez l'essayer, ce guide vous montrera les caractéristiques de base.
Pour de l'aide à l'installation, voir la page Installer ROX.
Après la mise en place du navigateur et avoir déballé toutes les autres applications, vous devriez avoir démarré ROX-Session pour établir ROX comme bureau principal. Puis il vous faut terminer la session, et la re-démarrer, et vous êtes prêt…

I've been busy recently making loads of improvements for dealing with binary releases and compilation:

• 0compile is now much easier to use.

  First, there's the new autocompile feature, where it takes the URL of a program and downloads and builds it, along with any required libraries. This should make it easier to compile and run programs like ROX-Filer on systems where up-to-date binaries aren't available.

  Secondly, 0compile is easier to use when compiling local source code (e.g. a GIT checkout) - you don't have to do the build in a separate directory and it takes the version information from the feed in the checkout, instead of taking a copy.

  Finally, it's better at tracking new versions of dependencies; if a new version is available then it will prompt you to do a clean build (or revert to the older version).

• 0release is a huge time-saver for making releases. Given the path to the local feed in a GIT checkout it can manage the whole release process for you: creating the release candidate, running the unit-tests, diffing against the previous version, signing the release with your GPG key, uploading to your server, testing the upload and updating the Zero Install feed. All you have to do is confirm the new version number and enter your pass-phrase.

  It's always been useful for releasing Python code, but for C programs it previously only published source code. Now, it can build binaries (possibly using remote or virtual machines to build for multiple platforms) and publish them too, automatically, for any program that can be built using 0compile.

• 0test provides an easy way to run your program's unit-tests with any dependencies, but the clever bit is that you can test combinations of versions. For example, you can test a new release against the last five releases of ROX-Lib with one command.

I've also patched ROX-CLib to use 0compile to compile. This has a number of advantages:

Experimental, but if you have a cluster of machines and don't want to have to download the same packages for each one, the new peer-to-peer sharing system allows a machine to discover that a nearby machine has the program it wants and copy it across directly!

I've been experimenting with making tutorial videos / screencasts:

The Zero Install Injector is named after the concept of "dependency injection". In this post, I'll try to explain what this means and why we use it.

The 2007 Zero Install survey is now up, so please submit your feedback there!

There's also some discussion on the LSB packaging list about third-party installation, including Zero Install.

A while ago Thomas Leonard wrote about Ubuntu integration and asked the question "Can we get rid of ROX-Session?". This inspired me to attempt to replace it with the Xfce session manager and it turns out that it is both easy to do and works very well.