Hi Chris,
Thanks for your comments. Based on what you say, I think I lean toward a generic PHP framework. I do want some Drupal integration, but probably not enough to warrant writing the whole thing in Drupal (I just want to create Drupal users from within my app).
Is CodeIgniter a good framework? There are so many PHP frameworks, I don't know which ones are worth researching in detail.
Chris Johnson wrote:
You can use Drupal as such a framework, but it probably won't make sense unless you either (1) already know Drupal and hence will save time by using it, versus learning a new framework, or (2) intend to use Drupal for something else anyway, in which case learning Drupal only instead of Drupal plus another framework again saves you time.
As Victor Kane points out, it also depends on what you want to do. If it is similar enough to what Drupal and its contributed modules can already do, it might be more efficient to use Drupal rather than a more generic framework.
Otherwise, there are a number of other good frameworks out there you could learn and use, and those frameworks might be more generalized over the entire problem space of "PHP application building".