The Unix heritage is strongly reflected on the Internet, and many Web development activities require Unix tools. The GNU tools fill the void for non-Unix shops, simulating a Unix environment on multiple platforms, including Windows. GNU tools are powerful, robust, widely used, and well-respected. Most university computer science departments use them in the classroom and for research. If you're not impressed with this quality and have money to burn, get the MKS Toolkit , a commercial package of nearly 300 Unix utilities.
Cryptographic software protects information and identifies who made the information.
The PGP development kit lets you incorporate the PGP algorithms into your code. PGP is well-tested and has no known security holes. Its key space runs to 1024 bits out of the box, which will remain uncrackable for decades. You must pay for the PGP development kit if you want to use it commercially, but it is free for other uses. Powerful cryptographic open source code is available but you are better starting off with the well-documented PGP kit before migrating to the more flexible open source solutions.