Best Of

I don't have experience with Textile conversions, but it looks like Markdown-adjacent, and I've never really had concerns about the processing speed. If you have a Vanilla forum using Markdown, it's doing the HTML processing in real time at pageload. It's pretty darn fast. I don't honestly think it would have a major impact on the migration time.

I don't know enough about Drupal to offer any specifics, but if you know of a way to pre-process and store the rendered HTML on the table in Drupal, that would be a nice way to sidestep the issue regardless of what platform you head to.

The existing Drupal 7 package appears to assume discussions & comments are in rendered HTML. Vanilla does have the concept of input formats, and the migration tool does have the concept of filtering data as its being processed. So your options are:

1. Do nothing and let the non-TinyMCE posts look like raw Textile.
2. Get someone to write a simple Textile parser plugin for Vanilla.
3. Get someone to add a simple Textile filter to the Porter.

Personally I'd go with option 3 if you're not super attached to Textile. There's already a PHP library for parsing Textile so I imagine it'd be pretty simple. I may be able to do that as well.

I use both Drupal and Vanilla and I don't think they are really comparable. Drupal is much bigger and more complex.

I'd suggest that the underlying issue perhaps is that the social media platforms have absorbed much of the demand for forums so that self-hosted forums and blogs are less common. There are still good reasons to host independently but it means reduced activity, although Vanilla has its own business model via cloud hosted forums which is a good thing from the point of view of open source users.

A lot of plugins are now included in the core software.

Tim