Programming

Note: external links open in separate windows. This site runs on Linux . We use Apache -- the most popular web server. Algebra.Com is well secured.

This site uses a combination of HTML, Perl, and mod_perl I use object-oriented features of Perl 5. I love perl! I use MySQL as the database backend.

Algebra.Com uses a content management system that I wrote myself. It is geared towards online teaching of math. To that end, it does two things: first, formulae that are typed by tutors or created by solvers, are displayed in proper mathematical form, like this: . See about formula rendering. Second, lessons and solvers are stored in the database (even though they "appear" to be HTML files to the reader).

Since solvers have an abstract interface, solvers can be invoked by tutors when they write solutions to student problems. For instance, linear systems or quadratic equations have pluggable solvers. That improves tutor productivity and reduces the amount of drudgery. I have a relatively sophisticated expression simplifier and solver with work shown.

Some sample code (all very dated):

• Quadratic Equation Solver (see Quadratic Equation Solver at work).
• Source code of my Config.pm -- perl module that helps me maintain site configuration
• This site uses almost no Javascript. Javascript is more trouble than it is worth, in my opinion.

Because this site uses perl, it works very fast. It can easily serve about 50 complex dynamic pages per second (see our stats). It is also capable of plotting graphs, pie charts, artificial intelligence and sound, a fully cross-linked dictionary, and a lot of other things that will be difficult to accomplish with less powerful languages, such as ASP.