In reply to
the old Drupal vs. Joomla thread's original post I would adjust its points this way:
Use Joomla 1.5 when:* you don't know much about PHP, mySQL or Apache and need an easy learning curve to learn as you build your first site in about 30-50hrs with a custom template and 5-10 extensions
* you or the site operator/s want to run and service the site themselves
* you want really well-organized support sites and services
* you or the site operator/s need an easy to learn and use administrative interface
* you want to deal with FTP as little as possible, are interested in Linux only to the extent that it looks like MacOS or Windows, and you never want to see a tarball, patchfile or command line interface.
* you want a professional-looking site with a lot of template options that are relatively easy to modify
* you like eye-candy or at least the option to add some very easily
* you want to display different kinds of content in lots of different positions on a page and change layouts without doing any coding or tedious configuration
* you primarily need basic CMS functions
* you need a highly customized feature set and don't mind the headaches that come from having to manage a bunch of extensions that have no central repository or update notification system
* you want extension developers with stable releases and accurately labelled pre-release stuff
* you don't mind having to do a lot of research to find out if various extensions are inter-compatible
* you don't mind being restricted to sections and categories and only one of each for your articles
* you don't mind that content means "articles" only
* you need only basic SEO features out of the box
* you want to sell and manage ads, run an events calendar, index/directory, classified ad system or are prepared to spend a lot of time building minimally passable solutions. (Short of coding your own extension, it's only possible to do an events calendar in Drupal 5 for the time being.)
* you don't need to operate more than one site through the same CMS
* you don't need users to have one login that will work on more than one site
* you don't need user groups and customizable roles-based permissions
* you're not building a membership site or don't mind paying for extensions that allow you to do this (the free option is tougher to work with.)
* you need an advanced rich text editor with image handling features and more
* you want to add an attractive and robust integrated forum that's mildly buggy or bridge in a popular standalone forum.
* you want no comments or a lot for slick choices for comment systems as extensions
* you don't mind a bare bones and unattractive forum and comment systems being part of the core, requiring you to disable them, replace them with bridged standalone forum software, or add a lot of extensions to make them capable
* you want to rapidly find quality extensions relevant to the features you want your site to have
* you need advanced localization and/or internationalization features
* you are prepared to continually monitor updates for the Joomla core and any extensions you install by watching all the relevant websites/rss feeds/newsletters
* you want really well-organized support sites and services
Use Drupal 6 when:* you are reasonably familiar with PHP, mySQL and Apache or else you are willing to learn by doing a lot of reading and wading through poorly organized documents and forums.
* you have 60-100hrs to invest in getting your first site operational with a custom template and 5-10 extensions.
* you or the site operator/s are a non-profit or NGO that has considerable familiarity with Drupal and ties (or the intent to establish ties) with established Drupal service providers in that market
* you or the site operator/s don't mind learning and using a difficult and disorienting administrative interface
* you don't mind tarballs, patchfiles and other habits and practices of people who think everyone uses or should use a UNIX-like operating system
* you don't care if your site looks generic, bloglike, and lacks quality coding in its html/css or else you can afford the time/help to build or learn how to build a highly customized template in Drupal
* you don't want to display different kinds of content in lots of different positions on a page and change layouts easily--you're willing to plan ahead on all this, do a lot of coding and tedious configuration, and then avoid changing anything in the future.
* you appreciate (or are prepared to learn to appreciate) the openness and complexity of the Taxonomy module
* you appreciate (or are prepared to learn to appreciate) content means everything
* you want every extension to be intercompatible with every other and whenever relevant tie into the core content and user permissions system
* you don't need a lot of extensions or don't mind using a lot of pre-stable releases until (probably) January-June 2009. If this is a problem you may prefer to use Drupal 5, but the upgrade to 6 (and eventually 7) will be laborious
* you don't mind spending a lot of time digging through Drupal.org to find extensions you might want to use
* you don't mind adding a lot of extensions to get basic CMS functions that are part of the Joomla core
* you need basic localization and/or internationalization features
* you don't need to sell and manage ads, run an events calendar or classified ad system or are prepared to spend a lot of time building minimally passable solutions. (Short of coding your own extension, it's only possible to do an events calendar in Drupal 5 for the time being.)
* you don't need an advanced rich text editor with image handling features and more
* you or your sites users who can create content know html and/or a markdown system
* you are crazy/very trusting and want the option to let users put PHP in content they create
* you don't mind a bare bones and unattractive but solid forum and comment system being part of the core, requiring you to disable them, replace them with bridged standalone forum software, or add a lot of extensions to make them capable of doing 50% of the things most forums and comment systems do
* you don't mind forum posts and comments being another kind of content rather than segregated and highly differentiated.
* you don't mind having a comment system that's a spam magnet out of the box requiring further extensions to authenticate posts
* you want or need multi-site management through a single CMS
* you need user groups and customizable roles-based permissions
* you need to run a membership, community, or social networking site that goes far beyond CMS functions
* you want your site to tell you when there are updates to the Drupal core and any extensions you've installed
* you are willing to dig through poorly organized support sites to find what you need