Source code is released under a MIT-license and hosted at git repository https://gitlab.com/janduja/extsort.
A compressed zip package can be downloaded at http://janduja.com/extsort/extsort-1.0-tar.gz.
extsort
extsort is a Common Lisp library for external sorting of Unicode text files. External sorting is a sorting process where the data to be sorted cannot fit entirely in memory: this is the case, for example, of big files.