We have a student working for us on comparisons between various LMSes here, and we recently moved on to Sakai. We've been looking a bit at installing it on an Ubuntu 9.04 and boy... is this a challenge. While there seems to be a few sources of documentation around the web (including on the Sakai website itself) on how to install it, they're all giving a 20 pages-long guide on how to install a specific version of Java (from sources), a specific version of Tomcat (from sources) and a specific version of Sakai (from sources as well). It seems like you need to be an active Java developer, used to the Tomcat stuff to actually get a chance to install it. Now that makes me recall our numerous users who complained about the fact that installing the videoconference in Dokeos 1.8.5 was impossible. Well, let me say that you require at least double the skills to install Sakai. The website mentions there are packages for Windows, Mac and Linux, yet the link to the corresponding page is broken (why's that, I wonder). An article from a Java developer gives you the impression it is a breeze to install, yes we are talking about a previous, outdated, version of Sakai. A big negative point for Sakai (yes, you can try it online, but obviously you might want to try out scaling and building your own site on a local server).