PlanetMath was conceived by Nathan Egge ("unlord" on PlanetMath) and Aaron Krowne ("akrowne" on PlanetMath-- yours truly) as a project to fill the void for a central repository for mathematical knowledge on the web, with a pedagogical slant. But we realized that we could do it in a way that would make it a community, built by the users, and that the users would be just as valuable as the content itself. There are now many grassroots-content sites like this (Wikipedia, Citeulike, Slashdot, Fark...), and PlanetMath represents a unique kind of hybrid of MathWorld, Wikipedia, and Slashdot concepts. We think that the end result has proven very useful to many people who are interested in learning math, who are already students studying math, or who make their living in mathematical professions.

The idea for the project was hatched by Egge, sometime around fall 2000, in response to the unfortunate removal of the great resource, "Eric Weisstein's World of Math" (or "MathWorld") from the internet. This incident created a void for a useful, comprehensive math encyclopedia freely available online, which we wanted to fill as quickly as possible. So Nathan and myself began brainstorming the concept and working out many of the problems inherent in a system that would do in real-time what had been static on MathWorld.

We also wanted to make certain that the users of PlanetMath would never have to worry about the removal of the content they had contributed in favour of commercial sale. So it is the express goal of PlanetMath to be an internet resource, first and foremost. We hope to achieve this with the aid of the GNU FDL, or Free Documentation License. Via the FDL, we ensure that the contributors retain the rights to their work.

Development began slowly after the initial flash of inspiration; as both Nathan and myself were very busy with school. Finally in the summer of 2001 we both graduated, and work really picked up pace. The core functionality of PlanetMath - the encyclopedia - is essentially complete. The site, however, continues to expand in scope (and it will probably never be completely "done") and functionality as we continue to add new ideas to it in order to enrich and strengthen the PlanetMath community.

Some credits:

• Aaron Krowne - design, coding
• Logan Hanks - coding
• Joel Irby - coding
• Nathan Egge - design, coding
• djao - licensing, testing, content
• ink - original logo
• zoner - new logo
• joe s. - initial hosting
• drini - testing, content
• undernet #math - moral support!

The current PlanetMath server is an IBM Netfinity 4000R, dual PIII-650 with a 20gb IDE hard drive. Thanks to Logan for use of this server.

The first PlanetMath machine was a mobile k6-III+ 450mhz chip with 384mb of ram and 6 and 20 gig IDE hard disks. Fun Facts: The AT case for this machine was second hand. The original 6 gig hard drive was rescued from the trash at Microsoft. The 20 gigger was acquired via barter (it is worth one microwave oven, apparently). The motherboard somehow still worked, despite the socket being rusted out by an overclocking experiment gone horribly wrong...)

PlanetMath Software :

• Operating system: Debian GNU/Linux 3.0
• Web Server: Apache 1.3, with mod_perl
• Code : Perl
• Math Rendering: LaTeX, LaTeX2HTML, netpbm, LaTeX, pnmutils, gs-aladdin

PlanetMath is currently hosted in Blacksburg, VA, with the Virginia Tech Digital Library Research Lab in the Computing Center.