Being Open Source code Proftpd is available primarily as source code for local compilation. There are a number of maintainers within the project who create the packaged builds for the primary platforms and distributions. For most users the packaged builds will prove to be sufficient and the least hassle route to installing Proftpd. However to use the daemon to it's fullest or to explore some of the more interesting features a local custom build will be required.
Proftpd was designed from the ground up to be both extensible and as secure by design as possible. Security is discussed in depth later in this document, however while there are no known security holes it cannot be said of this or any other piece of software that there are no problems waiting to be found. The extensibility is provided by means of a modular architecture which takes many lessons and features from the Apache webserver project. Almost all the functionality has been supplied by moving most functions into modules. This includes features such as "ls" and the authentication handling, this approach allows third party developers to provide additional modules to latch onto these hooks to add or extend the basics provided. Most of the more interesting modules have to be compiled in as they are not part of the standard builds. Unfortunately dynamically loadable modules are not available within the 1.2.x code tree though development and testing is planned for the 1.3.x development branch.