  We present TFORM, the version of the symbolic manipulation system FORM that
can make simultaneous use of several processors in a shared memory
architecture. The implementation uses Posix threads, also called pthreads, and
is therefore easily portable between various operating systems. Most existing
FORM programs will be able to take advantage of the increased processing power,
without the need for modifications. In some cases some minor additions may be
needed. For a computer with two processors a typical improvement factor in the
running time is 1.7 when compared to the traditional version of FORM. In the
case of computers with 4 processors a typical improvement factor in the
execution time is slightly above 3.
