I apologize for the limited browser and platform audience for this website.
Here are some of the reasons:

• I use "floating frames" (also called "inline frames") to display my problems and solutions (so that I can use special characters).
  Older versions of Netscape didn't support this feature, so I started developing everything using Internet Explorer.
• Then, somewhere into my many projects, I learned that Internet Explorer is much more "forgiving" than Netscape (Mozilla, Firefox, …) in interpreting HTML and JavaScript code.
  I discovered, after-the-fact, that some of my coding doesn't work in Netscape browsers.
• So, I should now be sure to test all my new coding in Netscape browsers, right?
• BUT, now, all my new coding uses MathML.
  I had figured out how to get MathML to work in Internet Explorer, by having people download MathPlayer.
  What about Netscape products?
• Well, I then discovered that there is a Universal Math Style Sheet that solves a lot of the problems regarding the display of MathML in a wide variety of different browsers and platforms!!! GREAT!!!
  And I've tested it, and it works!!!
• BUT, I will need to write all my code in XHTML, not HTML.
  In particular, Mozilla/Firefox natively supports MathML, but only in XHTML documents.
  And XHTML is much stricter than HTML.
• Plus, I need to learn XHTML.
  I need to learn XHTML anyways, because my online HTML course is now out-of-date and I want to turn it into an XHTML course.
• So, the next big project that I start from scratch (probably my Precalculus web site, after I finish the Algebra I, Geometry, and Algebra II sites) will, I promise, be coded in XHTML, will use the Universal Math Style Sheet, and will be accessible to LOTS more people!
• Also, it's just me doing all of this. (It's what I LOVE to do!) I have lots of formal mathematics education, but I am self-taught (yeh for the O'Reilly series!) for all my programming skills (HTML, JavaScript, MathML, PERL, TeX, PHP,  …)
• So, again, my apologies.
  It really does sadden me that my site is not more easily available to more people.
• By the way, I recently learned about SVG (Scalable Vector Graphics) which, like MathML, is an XML application.
  Just as MathML is the future of math on the web, SVG is the future of graphics on the web!
  I should be able to code all the mathematics-type graphics I need!
  Of course, I've got to learn SVG too (book on the way) …
  and, SVG needs to be embedded in XHTML documents …