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.
  

• Latest release: version 3.2 (June 2018).
  The main features added since the release of version 3.1.3 are as follows:
  input files may now contain an UTF-8 byte order mark, which some applications prepend to text files (3.1.4);
  increased performance in some 'extreme' cases (3.1.5);
  new option "onshellx", an extended form of "onshell" (3.2).
  Two errors present in previous versions have been fixed in version 3.2.

• Please report any error you may happen to find; the known problems are listed here.

• 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 (particle) number conservation rules for particle physics models  —  both "additive" and "modular" rules. 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, and thus QGRAF-R may also help to cross-check those files: if the rules found by QGRAF-R are not as expected then the model description is likely wrong.

• Programming language: FORTRAN 77.
  No binaries either, source should be compiled with gfortran, say.

• Latest release: version 0.6 (June 2018).
  

• Please report any error you may happen to find; the known problems are listed here.

• 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) as password too.
NB: accesses are logged; the username should be entered correctly, access will be denied if there is any typo or even some white space.

The following links let you pick either a tgz type archive or the individual files. There are two (incompatible) major releases to choose from; release 3 is recommended unless, for compatibility reasons, release 2 is really required.

• compressed archives ( tar + gzip )

• qgraf-3.2.tgz	size 304K	sha256sum 9b6a1974500d522ab8bd1d057f3c080591f2bc3b6dd21c92e95dbfe2fc5a6e39
  qgraf-3.1.4.tgz	size 279K	sha256sum b6f827a654124b368ea17cd391a78a49cda70e192e1c1c22e8e83142b07809dd
  qgraf-2.0.tgz	size 125K	sha256sum 0e3545cbb4171499f668d2dd03db05ddaf2b133468984fb7693facc33261c813

• uncompressed files

• qgraf-3.2

  qgraf-2.0

There is also a tool (designed for Linux/Gnu and compatible systems) 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 88K

  sha256sum fe2d04cd6f83b0dac1ed3fd885805ed9e2f83bcf388c354e3d8a50117ca53b87

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.