
The Framework itself is still free and open source, but they now also offer a free-but-limited Community edition, a more advanced Express edition ($5,000 per year per user), and a full-featured Pro edition. Metasploit was completely free, but the project was acquired by Rapid7 in 2009 and it soon sprouted commercial variants. One free extra is Metasploitable, an intentionally insecure Linux virtual machine you can use for testing Metasploit and other exploitation tools without hitting live servers. This makes writing your own exploits easier, and it certainly beats scouring the darkest corners of the Internet for illicit shellcode of dubious quality. It ships with hundreds of exploits, as you can see in their list of modules.

The extensible model through which payloads, encoders, no-op generators, and exploits can be integrated has made it possible to use the Metasploit Framework as an outlet for cutting-edge exploitation research. It is an advanced open-source platform for developing, testing, and using exploit code.

Metasploit took the security world by storm when it was released in 2004.
