I think it's really awesome that Microsoft and Xin Huang released the source code of their D3DX mesh parameterization library. Chuck announced it on his blog. There's a lot of good stuff in there, more than in any of the previous D3DX source code releases. I was never too happy with the k-means style clustering that we use in The Witness, top-down spectral clustering seems a much better approach. Also their stretch-minimization parameterization is certainly better than our plain LSCM. I wrote about our implementation in this article. A few people asked for our code and we released it here. However, today I'd recommend using Xin Huang's as a better starting point.