\label{About_Developers_Manual.tex}

The purpose of this document is to introduce developers people to
LON-CAPA, and enable them to start doing real work with the system
as quickly as possible. This should prove useful both to people who
already intend to develop with LON-CAPA, and to technical people who
are evaluating LON-CAPA to see if it suits their needs. 

The most daunting task facing new developers is understanding how
the whole system fits together; individual pieces are usually sensible
but like any large program it is difficult to understand the forest
by looking at just the trees. Therefore, this document will start
out with the highest-level overview of the system, which can be safely
skipped if you already know what LON-CAPA is. 

Next, we'll look at the major subsystems of LON-CAPA and how they
fit together at a high level, with enough detail to understand the
context a given piece of the system functions in. Appropriate pointers
will be given to the detailed documentation on the various subsystems,
so this section can be used as an expanded {}``Table of Contents''.

Then a brief tutorial in adding a {}``handler'' to LON-CAPA will
be given, enabling you both to understand how to add brand-new functionality
to LON-CAPA, and better understand the majority of the code in the
system which is in the form of handlers.

Finally, the last and largest portion of this document will be extremely
detailed examinations of the subsystems from a technical point of
view, including API descriptions suitable for use in programming.
Obviously you will not need to read this over entirely, unless you
really want to know what the system can do.