I have pushed SlackBuild script for letsencrypt project on my personal Github repository. It consists of 4 new Python modules and 1 for letsencrypt itself. It requires a lot of dependencies and most but above 4 are already on SlackBuilds project.
While it works on my initial testing, i can't really test on a real domain since i don't have full access on any domain. It would be really helpful if you have a domain and you want to have HTTPS digital certificates for free from letsencrypt project. The certificate will last for 90 days and you can use automatic renewal using the same program. You might want to see their blog post regarding the short life cycle for the certificate they issued.
In the letsencrypt SlackBuild, i also built apache and nginx plugin using their default configuration.
Please help testing the SlackBuild script