Resin is a web server and Java application server developed by Caucho Technology. Currently, only two versions are available: Resin (GPL), which is free for production use, and Resin Pro, designed for enterprise and production environments with a licensing fee. Resin supports the Java EE standard and features a mod_php/PHP-like engine called Quercus.

Resin (GPL) offers essential functionalities for web and application serving, while Resin Pro includes additional optimizations, such as:

Resin is primarily written in Java, with parts in C.

Resin Pro has been engineered to include:

Scalability

Development

Production Ready

App Server