QGRAF is a computer program that can generate  Feynman diagrams  and represent them by symbolic expressions; no graphical representation is generated, though.
It was written to assist in large perturbative calculations, in the context of Quantum Field Theory.

• Programming language: FORTRAN 77 (there should be some evolution in the next major release).
  Binaries/executables are not distributed; the source code has to be compiled and linked, eg with gfortran.
  Please report any error you may happen to find; the known problems are listed here.

• Latest release: version 3.1.4 (2012).
  This release is nearly identical to version 3.1.2, the differences being as follows:
  the source file is now compatible with gfortran without further ado;
  the input files may now contain an UTF-8 byte order mark, which some applications prepend to text files.

• The algorithm used to generate the diagrams is described — in its basic form — in the following article:

  • Automatic Feynman graph generation
    P. Nogueira
    J. Comput. Phys. 105 (1993) 279-289
    https://doi.org/10.1006/jcph.1993.1074

QGRAF-R is a computer program that can find  number conservation rules  for particle physics models; it can then identify (un)physical processes that break those rules, thereby establishing the non-existence of matching Feynman diagrams to all orders of perturbation theory.
The model files accepted as input are exactly those accepted by QGRAF.

• Some of the theory behind QGRAF-R is described in these papers:

  • From Feynman rules to conserved quantum numbers, I
    P. Nogueira
    Comput. Phys. Commun. 214 (2017) 83-90
    https://doi.org/10.1016/j.cpc.2017.01.025

  • From Feynman rules to conserved quantum numbers, II
    P. Nogueira
    Comput. Phys. Commun. 215 (2017) 13-19
    https://doi.org/10.1016/j.cpc.2017.01.027

A login window should appear when you first click on one of the links displayed below; then enter anonymous as username and (optionally) enter your e-mail address as password.
NB: all access is logged; the username should be entered correctly, access will be denied if there is any typo or even extra space.

The following links let you pick either a tgz type archive or the individual files. There are two (incompatible) versions to choose from; the latest one is recommended unless, for compatibility reasons, version 2.0 is really required.

• compressed archives ( tar + gzip )

• qgraf-3.1.4.tgz	size:  279K
  	sha256sum:  b6f827a654124b368ea17cd391a78a49cda70e192e1c1c22e8e83142b07809dd
  qgraf-2.0.tgz	size:  125K
  	sha256sum:  0e3545cbb4171499f668d2dd03db05ddaf2b133468984fb7693facc33261c813

• uncompressed files

• qgraf-3.1.4

  qgraf-2.0

There is also a tool (designed for 'unix-like' environments) to convert model and style files written for version 2.0 into files suitable for versions 3.x.

• q2to3.tgz	size:  60K
  	sha256sum:  3a08c60cf7addd212570df4baea472b8194144b8d5e29dfb031549f92adbfe87

For now QGRAF-R should be treated as a beta-release; it seems to work, though.

• qgraf-r.tgz	size:  78K
  	sha256sum:  6a7db3dcf3c161c86a383ca6c821b70f637951238035d53b7994240ff657f96b

• Further links may be found on this web page or this other web page.

To report a problem or send in some other useful comments, please see here.