Are you interested in procedural walking, rather than using an artist's animation tool/keyframe editor? If so, that would be a good keyphrase, "procedural walking," though it still might not be obvious which are the useful search results. Maybe "procedural locomotion" also.

Here's a couple of articles of interest, related to procedural or generative walking/locomotion. These don't really related to making animations using artists tools, at least not directly.

Versatile Walk Engine

You'll find links to lots of related articles (associated by reference to the first link):

Versatile Walk Engine summary with citations

This one is quite interesting but it focused on bipeds and is not really talking about a general purpose approach or full automation:

Automated Semi-Procedural Animation for Character Locomotion

Here's a couple of relevant links on the Spore animation system, which supports skeleton's of pretty arbitrary topology:

The easy version:

How to Animate a Character You've Never Seen Before

And, the hard version:

Real-time Motion Retargeting to Highly Varied User-Created Morphologies