I recently came across a discussion on LinkedIn regarding the longevity of Drupal. Alex, who posted the question mentioned about how the Post Nuke CMS forked into Zikula, which has lost a lot of its past popularity. We can see how the popularity shifted back in 2005 with Drupal leading the way. We can also see some of that trends here with Google Trends.
A lot of other users have posted their views on this. Some have mentioned that Drupal has been around for 8 years, while others mentioned that it is used by a lot of major companies. My view on this is as follows:
1) Drupal will be around for a while because not only are their major organizations using it, but also that these organizations invest in it. When I say investing in it, I mean that a lot of major organizations sponsor modules and have their staff dedicate time to enhance the Drupal system. A few examples of that include the sponsorship of the multi-lingual modules by Sony BMG, and how Economist.com encourages their staff to contribute time to the Drupal project.
2) Drupal is based on an infrastructure that is growing. Drupal is on the LAMP stack. MySQL is still growing. While it is true that the Oracle acquisition of Sun may have an impact on the product. At the end of the day, MySQL is used by a lot of large organizations. It is here to stay. Looking at the other components of the LAMP stack, Linux remains highly popular for servers and Apache remain one of the most popular web servers.
3) Training can be obtained cost effectively. Unlike SAP, Orcale, it is not that costly to receive training for Drupal development. After all, Drupal is based on PHP, which programmers can easily learn to use as long as they have a solid technical background. There is a learning curve, but compared to paying thousands of dollars just to get oneself the materials for training, Drupal training has a lower barrier of entry.