2 projects are written in Perl, listed alphabetically. They are Movable Type and Webmin. Split across content management systems and servers and proxies. 38 records do not record this field, and cannot appear here either way. Counts only projects with momentum; the full list has the rest.
M
Movable TypeCommercial publishing and blogging system from Six Apart that publishes static pages, dynamic pages or both from templates.
W
WebminWeb-based administration tool for Unix-like servers that configures system files and server applications such as Apache HTTP Server, BIND and MySQL.
What is the best web software written in Perl?
We can't tell from here. What suits an editor-heavy marketing site can be wrong for a static documentation site. The list is alphabetical and nobody paid for a place on it.