Inexpensive, Flexible and Extensible

Because Drupal is free and open source and nearly all of its modules are as well, Drupal provides an inexpensive path to building an ELN. It is also relatively easy to set up and is flexible through using appropriate modules from the thousands that are available on the Drupal website. You can also write your own custom modules fairly easily. This is one of the biggest advantages to using Drupal over other ELN alternatives.