Dual IK/FK solver really needed!

@Jason van Gumster: Very deep analytics... But Ubisoft is using "CS_Biped", even for quadrupeds... Do U know why? Cuz "Max Biped" based on same system... And if U will watch this video again, U will notice - this is addition IK solver, not replace for old version.

@Slozhny: The point, still is to present this in a Blender context so Blender developers have an idea of how to implement it and how it would work in Blender . For instance, with a solver like this when would riggers ahve a need to just the regular IK solver?

Blender's workflow is different from other applications. The controls and interface often can't be the same as in other applications. This is why I'm asking you these questions. I think this solver itself is very cool, but right now you don't have a proposal. You have a video for someone else's software.

@Jason van Gumster: I not really unterstood what a differet between maya, max or blender rigs control or components (same bones, links, controllerz, constraintz, setup elements). Like I said before, it should be additional (optional) IK solver. So if U means "how to made it" ???... I'm not a coder, and I can't make it by myself (like Felix Joleanes). But I think blender team have guys, who can make "reverse enginering" of this plugin (wich consists of two files).... or haven't???

@Slozhny: The interface and workflow are different. For instance, in Maya, you don't add bones, you add joints. There are still constraints, but the way you add them and control them is different. None of the other software has quite the same concept as Blender's Armature object. I don't mean how to make it. You don't need to know how to code it. I mean that you should explain how will a Blender user will use this .

Imagine you're making a tutorial that explains to how to use this feature in Blender. Walk through the rigging workflow that Blender currently has for IK. Now walk through that same workflow to use this IK/FK solver. Explain when a user would use the IK/FK solver instead of the IK solver... and the reverse. It's often helpful to include mock-up images of how you think it will look in Blender. These are the things that make a good proposal.

I did not understand all that's said in the video (not my native language & the accent makes it more difficult to me). But if it's "just" a different solver, maybe it could be added to Blender via the Armature's INverse Kinematics panel which presents an IK Solver drop-down menu:

And if its a totally different IK system with specific options and user inputs needed, then maybe it will require an entire new Bone Constraint :

@loic.dautry: Exactly