why not MathML? its a standard, its already supported by mozilla/netscape, and their derivatives, and sooner or later MS will have to add it to IE.. i just think this is the way to go...
As markup used for *input*???
HTML: 2 + 2 = 4
PediaWiki: 2 + 2 = 4
LaTeX: $2+2=4$
MathML: <math><mrow><mrow><mn>2</mn><mo>+</mo><mn>2</mn></mrow><mo>=</mo><mn>4</mn></mrow></math>
HTML: <pre> −<i>b</i> ± √(<i>b</i><sup>2</sup> − 4<i>a</i><i>c</i>) <i>x</i> = ---------------- 2<i>a</i> </pre>
PediaWiki: −<i>b</i> ± √(<i>b</i><sup>2</sup> − 4<i>a</i><i>c</i>) <i>x</i> = ---------------- 2<i>a</i>
LaTeX: $$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$
MathML: <math><mrow><mi>x</mi><mo>=</mo><mfrac><mrow><mrow><mo>-</mo><mi>b</mi></mrow><mo>±</mo><msqrt><mrow><msup><mi>b</mi><mn>2</mn></msup><mo>-</mo><mrow><mn>4</mn><mo>⁢</mo><mi>a</mi><mo>⁢</mo><mi>c</mi></mrow></mrow></msqrt></mrow><mrow><mn>2</mn><mo>⁢</mo><mi>a</mi></mrow></mfrac></mrow></math>
-- Toby