I know a number of people that have transitions applications from ColdFusion to PHP/MySQL.

ColdFusion was super popular around 98-2000, but from what I've been able to determine, it seems to have really waned in popularity in favor of other scripting language, most notably PHP.

The people I know that have transitioned seem to be universally happy with their decision, though the actual process of porting over was time consuming, requiring pretty much complete re-coding of everything.

The good news is, I think there are a *lot* more PHP programmers out there than ColdFusion programmers, so the availibility and options out there for you should be much better.