[Mono-list] targeting and running a specific .Net version

[Miguel de Icaza]

Hello,

> when I look under mono/lib/mono/ I see 4 different versions:
> 
> 1.0        2.0        2.1        3.5 

I have updated the documentation to explain what this means, attached is
the documentation:

PACKAGES
       Depending  on  the  invocation  for the C# compiler (mcs, gmcs, or
       smcs) you will get a default set  of  libraries  and  versions  of
       those libraries that are referenced.

       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# com‐
       piler includes the -pkg: command line option that is used to  load
       specific collections of libraries.

       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:

       mcs    References the PACKAGEBASE/1.0 directory

       gmcs   References the PACKAGEBASE/2.0 directory

       smcs   References the PACKAGEBASE/2.1 directory

       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.

       Software providers will distribute software that is installed rel‐
       ative  to  the PACKAGEBASE directory.  This is integrated into the
       gacutil tool that not only installs  public  assemblies  into  the
       Global  Assembly Cache (GAC) but also installs them into the PACK‐
       AGEBASE/PKG directory (where PKG is the name passed to the  -pack‐
       age flag to gacutil).

       As  a  developer,  if  you want to consume the Gtk# libraries, you
       would invoke the compiler like this:

            $ mcs -pkg:gtk-sharp-2.0 main.cs

       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:

            $ pkg-config --libs gtk-sharp-2.0

       Usually this merely references the libraries from PACKAGEBASE/PKG.

       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.