This list was provided by Carlos O"Ryan <coryan@uci.edu>.

1) Eliminate #includes or substitute forward declarations for them.

2) Find #includes that are only used to satisfy some inlined code, evaluate
if the inline code is in the critical path and if not take the code
out-of-line and eliminate the #include.

3) Check if the files are including helper classes not used in the interface
of the ORB but in its implementation.  If that is the case the offending
classes should be moved to their own #includes and used only in the required
.cpp files.

4) Search for repetitive code in the .h files and change that to templates
or other mechanism that reduces parsing time.

5) Search for code that is currently in OS.h and could be moved to a
separate ace/OS_Foo.h file (see my posting about the compilation time for
OS_String.h).

6) Currently corbafwd.h is there only because we needed to support compilers
without namespace support.  After 1.2.1 all the compilers we (DOC group),
Riverace and/or OCI support will have namespaces, we can then break
corbafwd.h in multiple pieces and use that to reduce the parsing time and
maybe the number of #includes.