Coordinate transformations

I am trying to learn about WKT projection information and how projects are actually done in GDAL and PROJ.  Needless to say, I knew very little before this week and I still do not know very much.  First some links:

http://www.geoapi.org/snapshot/javadoc/org/opengis/referencing/doc-files/WKT.html#TOWGS84
http://spatial-analyst.net/ILWIS/htm/ilwisapp/find_datum_trans_params_methodpage.htm
http://edndoc.esri.com/arcsde/9.2/concepts/geometry/coordref/coordsys/geographic/transformationmethods.htm

So what is the best resource to learn about various methods?  e.g. Molodensky Badekas Bursa Wolf

Google low level C++ APIs

This is one of those questions that keeps coming up... "What core/low-level libraries has Google released as open source?"  As someone who works inside of Google, I already know a lot of them and when I work on external code (e.g. GDAL) I have to work extra hard because the tools I normally reach for are not there.  One of those is the C++ strings substitute.h.  I just went looking and found it:

https://github.com/google/lmctfy/blob/master/strings/substitute.h
https://github.com/google/protobuf/blob/master/src/google/protobuf/stubs/substitute.h
https://github.com/google/supersonic/blob/master/supersonic/utils/strings/substitute.h
https://github.com/google/sensei/blob/master/sensei/strings/substitute.h

The question then becomes, where do I find the latest open sourced version and how do I use it in a library that will be used by many other people such as GDAL or libais?  I probably have to move it into a gdal or osgeo namespace or it's going to clash at link time.  If it's just an end tool, there there is less worry.