Lately, after beeing presented with the magnificient productivity - performance problem by

Of course,

But seeing that many around here know an actual fair share of multithreading and/or the game industry inner workings, I cannot restrain myself from asking:
What libaries do you know that allow you to build a portable (linux - windows) multithreaded task scheduler library in C++ robust/flexible enough to deal with the uglinesses of game engines?
Heck, be it even "just" a portable multithreaded for-loop implementation.
I've found around here (forget where, sorry D: ) the magnificient Cascade PPF Paper, but I haven't been able to find the library itself. Hence, this post.
As always, all the creative smog that infests this place numbs minds and provokes delusional thoughts (that's a compliment there); so I'll open a post on the off-topic game section with the details on the wanna-be game this would be used on if any of you has sincere interest in knowing about it. (Because if opening such a post means ending up throwing a full day at it, as it's first public notice demands, and that's not gonna happen without provocation).