Drupal is also often compared with other open source content management systems including Joomla, Plone, Scoop, Silverstripe, Typo3, Graffitti, Moveable Type and Wordpress. There are characteristic features to all of these systems that make them appropriate in certain contexts, and most of them compare favorably to Drupal in one category of operation or another. Few of them, however, are capable of offering the balance between performance and functionality found in Drupal.
Another common alternative platform to Drupal is Ruby on Rails. We really don't have much to say about Ruby except that it is a framework moreso than a platform. There are some characteristically challenging web development tasks that are quite easy to do with Ruby, and there are others which are infinitely more complicated than they should be.
One big difference is the fact that Ruby lacks the refined data object model found in Drupal that ensures interoperability between various aspects of the system, such as adding new modules to modify the operations of others. Whereas Drupal offers a self-generating database schema for many modules and underlying components of the platform, Ruby on Rails emphasizes a design philosophy holding that simplification of code conventions leads to better outcomes. While this all sounds good in principle, we have found there are certain tasks that make adherance to this philosophy an ideal moreso than a practical goal and breaking free from these conventions when necessary a daunting task (especially when integrating with external systems).
Symptoms: An authorized Drupal user loses "edit" access to nodes they've created, even if they have appropriate node (or other module) access permissions. Or, user cannot edit a node that should be editable by them, based on access control or node access settings. No errors or warnings are presented to the user. Nothing in the Drupal watchdog log.
Possible Cause: The user does not have permission to use the input filter currently assigned to the node. (An administrator or other privileged user may have changed the input filter settings, or, input filter permissions may have been changed to exclude the node author since the node was created. As a result, the user never had, or no longer has permission to use the input filter associated with the node.)
A minimum base installation requires at least 3MB of disk space but you should assume that your actual disk space will be somewhat higher. For example, if you install many contributed modules and contributed themes, the actual disk space for your installation could easily be 40 MB or more (exclusive of database content, media, backups and other files).