Dear MMB Users, I have now posted MMB 2.11 for OSX, Windows, and Linux. The following is from the "What's New" section of the Reference Guide: In release 2.11 the length units are Ångströms rather than nanometers, consistent with molmodel’s conventions. This makes it easier to relate various stiffnesses, energies, and other physical quantities. I have created the rootMobilizer command, which for the first time allows you to connect a chain to ground using a Weld mobilizer (rather than the default Free) – this reduces the degrees of freedom of the system and saves compute time, for the often-found situation in which one or more chains are fixed to ground. There is also now a constrainChainRigidSegments command, which constrains all rigid segments in a chain either to ground or to a specified residue in the same chain (permitting center of mass motions). One application of this is to flexibilize an interface and allow (or not allow) center of mass motions, e.g. to equilibrate clashes on that interface. I welcome comments on the release. Happy modeling! Sam