I know little about Fuel (just discovered it today), but my take on it is that it is pretty much exactly like Kohana 2.3, but less complex and verbose than Kohana 3 (because Ko3 changed so much from 2.3).
Symfony/Symfony2 is a much more heavyweight framework -- much more "enterprisey", which I don't mean in a bad way -- the Symfony folks seem to have a much better understanding of OO patterns and best practices than most PHP folks, and if you're building a very large app that needs to be scalable, extendable, etc., Symfony is the way to go. But for more straightforward CRUD apps or sites without humungous user bases or numbers of pages, Kohana/Fuel is a better fit, IMO. The usual lightweight vs. heavyweight tradeoffs.
I would like to clarify something: We're not exactly (or pretty much exactly) like anything. Some small parts may have been taken from other frameworks but the whole application flow (Request, Response), autoloader and most of the classes were written from scratch. Being (partially) responsible for classes like Validation, Form, Cache, ViewModel and packages Auth & Orm I can be very clear that while inspiration may have been drawn from many sources they were build specificly & uniquely for Fuel without being ported/rewritten/copied from anything.
We do use slightly modified versions of Kohana's querybuilder & View classes (something we're very upfront about, and from Ko3 btw not Ko2.3) but the framework by and large was build by us originally. And if parts were taken from other frameworks it is mentioned explicitly in the code, but those are the exceptions rather than the rule.
Apologies if I am misrepresenting the project (as I said, I know very little about Fuel, just discovered it via this thread) -- didn't mean to put you on the defensive.
I didn't look at the underlying code at all, just browsed through the docs and to my eyes the "API" or "structure" of Fuel looked very similar to Kohana, which is a HUGE compliment coming from me, as Kohana is (was?!) my favorite PHP framework. Definitely not accusing anyone of stealing code -- just trying to answer the guy's question. I don't think anyone could argue that if you compare Fuel to Kohana and Symfony [as was the question], Fuel is WAY closer to the Kohana end of the spectrum.
Anyways, I'm really looking forward to trying this out on my next non-CMS project -- thank you for creating this.
