There is no technical reason why a versioning system cannot be written in pure Perl. A very primitive "file level" versioning system exists with Net::FTP::Versioning
(warning: I never tried it).
But, it would be a major effort to develop a complete one and at best you only copy the services that are already provided by the many already existing versioning systems.
Far better to apply to the sysadmin of your server and after some groveling and handing over of appropriate presents (think: beer, chocolates, cookies, iPads, fast cars, ...) have him/her install one of the existing versioning systems.
A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James
My blog: Imperial Deltronics