The last couple of days I’ve been working on improving libM4RI for sparse-ish matrices. The matrices I am talking about here are still represented as dense matrices but have non-uniformly distributed entries. While PLUQ factorisation is still very very (very very) slow for e.g. half rank matrices, things are getting better for M4RI matrix elimination.
The updated sources are available on bitbucket. I will probably cut a new release very early next year.