<Chapter Label="Preface">
<Heading>Preface</Heading>
This is one of the three main &GAP; books.
It describes most essential changes from previous &GAP; releases.
<P/>
In addition to this manual, there is the <E>&GAP; Tutorial</E>
<Alt Only="HTML">(see <Ref BookName="tut" Label="Preface"/>)</Alt>
and the <E>&GAP; Reference Manual</E>
<Alt Only="HTML">(see <Ref BookName="ref" Label="Preface"/>)</Alt>
containing detailed documentation of the mathematical functionality of &GAP;.
<P/>
A lot of the functionality of the system and a number of
contributed extensions are provided as &GAP; packages,
and each of these has its own manual. New versions of packages are
released independently of &GAP; releases, and changes between
package versions may be described in their documentation.
<P/>
</Chapter>