This is a comparison of most popular content-management-systems Drupal 6x and Joomla 1.5 series.
Drupal pros: free, professional coded, multilang, multisite, performance, great community, flexibility, power, role-based user access, flexible content types, excellent taxonomy system, seo friendly urls, multi-db-support
Drupal cons: hard to learn, poor online themes, not-core-included important modules, e-commerce, too simple looking forum system,
Joomla pros: free, good coded, multilang, easy learning curve, quality templates, ssl-login-support
Joomla cons: high loads, not seo-friendly urls, not-flexible, confusing arc.
Joomla is the best choice for beginners. Drupal has excellent online-documentation and great community but it is not enaugh for beginners with less time and poor knowledge.
You can install both cms over a webinterface. Joomle core comes with Media Manager, Language Manager, Contact Management, Banner Management, Polls, Search, WYSIWYG editor. Drupal core comes with Collaborative Books, Friendly URLs , Search, Polls , Blogs, Blogger API support , Content syndication , News aggregator , Multi-language , Discussion forums. There are also different installation profiles on Drupal site. Drupal modules should be uploaded to modules directory. Joomla components (.zip packages) should be installed over webintarface. Updating Drupal core is much easier as you can put your own modules, templates, config files in seperate directories, which will not be overwritten.
Drupal has a clear architecture, uses blocks for right-left-top-bottom-.. etc blocks and modules for plug-ins. Joomla has a bad-named system; uses "modules" for blocks and has components, extentions, mambots etc as modules, which are confusing by names. Both cms have seperated templating systems. Drupal is oop but does not use php-classes in code. Drupal is "database-independent"(Mysql, Postgresql, ...), Joomla using MySQL.
Drupal looks more powerful. APIs, Views, CCK make Drupal the winner.
If Joomla were a barebone Drupal would be a desktop-computer. Joomla is easy to start but hard to customize. Drupal is much more flexible. ie: You can add capctas to each form on Drupal but not on Joomla.
Drupal would be the best choice for high-traffic sites (because of its good caching system and optimized code).
Drupal is a good system with bad looking-templates. Joomla has much more professional designs, both free and premium. There are live demos of Drupal's most popular themes on www.themegarden.org.
Both cms have good search systems. Drupals advanced search is very flexible.
Drupal has excellent url system using path(core) and pathauto modules. Each content item is avaliable under "node/123" like Content_ID too. Joomla has seo modules too but they are poor compared to Drupal.
Drupal wins, there are much more professional developers on Drupal forums than Joomla. Most Drupal-module coders make it possible that their modules communicate with other modules using Drupal APIs.
Management & Administration
Drupal has bad looking but easy-to-find admin area. Drupal does not need extra admin login, rights are loaded with user/root login. Drupal has no admin groups by default, there is also one root-admin with userid #1. But Drupal is very flexible you can create new roles with different access settings and assign users to this roles. Joomla uses completely seperated admin area with extra login. Joomla has a couple of both user and admin-moderator levels. Drupal has poor backup-recovery functions. Joomla has better solutions at the moment. Joomla lock content to prevent double content editing from multiple editors same time.
Content, Categories, Menus
Drupal wins with excellent taxonomy-system and flexible menu system. There are also image-upload, file-attachment, WYSIWYG modules for both cms. Joomla has options for meta-data description, keywords for each content item but Drupal not.
E-Commerce was one of two most important Drupal Weakness with Forum system. Now there are two e-commerce modules(Ubercart and E-Commerce) on Drupal site. Joomla's Virtuemart is an excellent shopping cart.
At the moment Joomla looks more popular than Drupal, probably because of high number of newbie users(higher Google-PR, better Alexa rang, better placement on Google-Trends and Twitter, more backlinks). But Drupal -the system of future- is getting more popular everyday. Drupal can be next CMS champion with version 7. Drupal's website is more popular.
Drupal is very popular in:
Czech Republic, India, Indonesia, Russian Federation, Hungary, New Zealand, Belgium, Norway, United States, Canada
Joomla is very popular in:
Indonesia, Netherlands, Russian Federation, Malaysia, Switzerland, Czech Republic, Italy, Germany, Austria, Portugal
Drupal's Google Pagerank: 8
Joomla's Google Pagerank: 9
Drupal's Alexa Rang: 1.285
Joomla's Alexa Rang: 1.016
Use Joomla for a small to middle website if you are a beginner with less experience, less time and less money. Use Drupal for a small to big website if you have web programming experiences, enaugh time and enaugh money for layout-designers.