[nmz]

For bignums, have you tried this?

https://web.tecgraf.puc-rio.br/~lhf/ftp/lua/#limath

luajit does have integers (try 5ull+6), bit operations via the bit library (absorbed from lua5.2)

[pmarreck]

How does imath compare to gmp?

[nmz]

In lua? It works for one.