AMP, which usually stands for Apache, MySQL & PHP, is a bundle of free and open source software, which developers can use to run servers in their own computers.

It spares you the need to purchase your own server. Working locally also means you get the maximum possible speed.

If your bundle is portable, you don't even have to install anything. Instead, you just plug and play the downloaded bundle.

Also, with no host involved there's no one stopping you from declaring “mbstring.internal_encoding = UTF-8” in php.ini.

Hopefully, this will increase motivation to develop glFusion's plugins.

Wikipedia's List of AMP Packages contains such bundles for every possible system, including Windows.

While glFusion requires specific databases and programming language, it does not have server requirements. Thus you are not limited to Apache, which is an overkill in the case of programming related development, such as a CMS and its plugins.

A much lighter server called lighttpd has support for Windows. In the external links of Wikipedia's entry for lighttpd you can find the portable program Lighty2Go that contains lighttpd/MySQL/PHP. You can run glFusion in it without installing anything on your operating system (everything is stored under Lighty2Go's path).

Sometimes you need to develop in several operating systems at once. If you need a AMP stack that has versions for both Windows, Mac-OS X, Solaris, and Linux, try XAMPP at apachefriends.org