In a CMS discussion group I belong to, someone recently asked:
- Very clean core code.
- Good project leadership from Acquia.
- Some very good developers available for hire.
- Fewer clowns available for hire (you can either code Drupal or you can't, it's harder to fake it).
- Can be made very server efficient in the right hands (scaleable).
- Less ready made drop-in plugins. You're going to have to get your hands dirty almost every time.
- More imposing default user interface.
- Fewer developers.
- More expensive developers.
- Good menu system.
- Strong static page structure (cf. weblog).
- Built-in membership/community features.
- Long time on the market.
- I'm searching here.
- Built-in performance pretty sluggish/clunky.
- Horrid built-in URLs.
- Weak weblog section.
- Hard to theme. A Mambo/Joomla site looks like Mambo/Joomla, like it or not.
- Nasty, nasty core code. Very difficult to fix broken items.
- Fractured community (never healed after Joomla/Mambo split back in 2006).
- Most good plugins are pay.
- Huge community.
- Easy to optimise for performance thanks to Donncha O Caoimh and Frederick Townes. Great work guys.
- Easy to theme in a unique way. A WordPress site does not have to look like a WordPress site.
- Great plugin architecture.
- Plugins for everything.
- Lots of great professional developers.
- Fast development cycle. Improvements every year.
- Fairly weak core code (in comparison to Drupal, but not Joomla!) but core getting better every year.
- Weak static page management without adding plugins. Easily fixed with said plugins.
Serbo-Croatian: Drupal protiv Joomla protiv WordPress: Programersko gledište