+.SH PACKAGES AND LIBRARIES
+When referencing an assembly, if the name of the assembly is a path,
+the compiler will try to load the assembly specified in the path. If
+it does not, then the compiler will try loading the assembly from the
+current directory, the compiler base directory and if the assembly is
+not found in any of those places in the directories specified as
+arguments to the -lib: command argument.
+.PP
+The compiler uses the library path to locate libraries, and is able to
+reference libraries from a particular package if that directory is
+used. To simplify the use of packages, the C# compiler includes the
+-pkg: command line option that is used to load specific collections of
+libraries.
+.PP
+Libraries visible to the compiler are stored relative to the
+installation prefix under PREFIX/lib/mono/ called the PACKAGEBASE and the
+defaults for mcs, gmcs and smcs are as follows:
+.TP
+.I mcs
+References the PACKAGEBASE/1.0 directory
+.TP
+.I gmcs
+References the PACKAGEBASE/2.0 directory
+.TP
+.I smcs
+References the PACKAGEBASE/2.1 directory
+.PP
+Those are the only runtime profiles that exist. Although other
+directories exist (like 3.0 and 3.5) those are not really runtime
+profiles, they are merely placeholders for extra libraries that build
+on the 2.0 foundation.
+.PP
+Software providers will distribute software that is installed relative
+to the PACKAGEBASE directory. This is integrated into the
+.I gacutil
+tool that not only installs public assemblies into the Global Assembly
+Cache (GAC) but also installs them into the PACKAGEBASE/PKG directory
+(where PKG is the name passed to the -package flag to gacutil).
+.PP
+As a developer, if you want to consume the Gtk# libraries, you would
+invoke the compiler like this:
+.nf
+
+ $ mcs -pkg:gtk-sharp-2.0 main.cs
+
+.fi
+The -pkg: option instructs the compiler to fetch the definitions for
+gtk-sharp-2.0 from pkg-config, this is equivalent to passing to the C#
+compiler the output of:
+.nf
+
+ $ pkg-config --libs gtk-sharp-2.0
+
+.fi
+Usually this merely references the libraries from PACKAGEBASE/PKG.
+.PP
+Although there are directory names for 3.0 and 3.5, that does not mean
+that there are 3.0 and 3.5 compiler editions or profiles. Those are
+merely new libraries that must be manually referenced either with the
+proper -pkg: invocation, or by referencing the libraries directly.
+.PP