To all those currently using the proto expression template toolkit at boost/xpressive/proto (all 2 of you, you know who you are), this is a heads up that the code has been rewritten, and the interfaces changed considerably. The changes have been committed to HEAD. The goals of the rewrite were many, but to sum up, the new code has a simpler, more uniform interface, integrates better with Fusion, and seamlessly supports ET nodes stored by value or reference. As a perk, xpressive now compiles 2x faster with vc7.1, and 25% faster with vc8. (No significant change with gcc.) The people most interested would be the Spirit people. The changes are specifically to make proto a better platform upon which to build Spirit-2. Now that I have an interface I can live with, I'm more inclined to write docs, and I will. The old proto v1 code from 1.34 now lives at boost/xpressive/proto/v1_ in the boost::proto1 namespace. -- Eric Niebler Boost Consulting www.boost-consulting.com