From version 0.1.6a to 0.1.7:

• Support for multi-domain meshing. That is, it is now possible to specify a problem domain that must be meshed as two or more (max: 31) adjacent regions, with the boundaries between them meshed consistently. This is the biggest addition to this version of GRUMMP.
• Improved boundary data input format. This was necessary to support multi-domain meshing, and the new format was designed to be extensible, with an eye towards meshing from non-polygonal/polyhedral data.
• Improved geometric calculations. GRUMMP often needs to know the orientation of $N+1$ points in $N$ dimensions or whether a given point is inside the ball formed by $N+1$ other points. Earlier versions used simple floating point arithmetic to determine these things, and sometimes ran into trouble as a result. This version incorporates adaptive-precision versions of these predicates that were developed by Jonathon Shewchuk of U California, Berkeley, while he was a PhD student at Carnegie Mellon University.
• File name changes. All GRUMMP include files^A.2 are now prefixed with GR_ to avoid naming conflicts. Also, in deference to non-case-sensitive operating systems, all C++ files now have a .cxx suffix instead of .C.
• Minor bug fixes. All but a couple of the problem input files sent to me after version 0.1.6 now work.
• Changes to quote handling for I/O generation. The old way of handling non-keyword text in I/O template files made it impossible to have
  
  x 0.5 y 0.7
  
  as a vertex coordinate line; the `x' and `y' were not handled properly. These changes affect all cases where quotes are used in template files, so check any template files you have created to make sure they are compatible with the new form of quote handling.
• Unified lex input files for I/O generation. All input generation is now done from a single lex file, and all output generation is done from a (different) single lex file. This removed inconsistencies between the 2D and 3D versions of the I/O generation code.