This is a new assignment programme and one of the best available. It is still being developed and has a very good mailing list and manual. The preferred operating system is Linux (or MAC). It is mainly written in Python and users can write their own macros using the API.
This is a very popular assignment program, but is apparently no longer being actively developed. It is written in Python and users can write their own extensions. It is free for academic users.
Another widely used assignment programme which is still being actively developed and is free for academic users.
A new NMR assignment programme by Greg Benison. Alongside the usual strip-plots etc. it also incorporates the higher-order spectrum principle, a way of assigning peaks in 3- and higher dimensional spectra that doesn’t rely on peaklists. It is free and operates under a GPL license which means anyone can borrow or contribute code.
This NMR assignment programme has essentially been superceded by CCPNmr Analysis.