Download Squad

What does the 5 in Calc5 stand for? I have no idea. Rest assured, though, that this slick Ajax calculator does support most numbers, including those greater than five. At first blush there's not a lot to set Calc5 apart from the crowd. It works as advertised. But then you get into the advanced math and graphing functions, and that's where Calc5 really stands out. While it's distinctly lacking in documentation, the built-in samples will get you started. You can use unlimited variables, you can do derivations, you can find derivatives, and more, but most impressively you can make fast, attractive graphs, both 2D and 3D. The 2D graphs are very cool--smooth lines, and a Google Maps-like interface that lets you pan and zoom with the mouse. The 3D graphs aren't quite as cool--they lack the pan and zoom features--but still. 3D graphs will always be cool. The site automatically saves your previous calculations (via cookies), which is handy, but there's no built-in permalink system for sending calculations or graphs to your friends and colleagues. I can only assume this functionality is coming.

There are a couple undocumented features (well the whole app is undocumented, so take that how you will) I discovered that you might find useful, though:

1. Pressing Ctrl+Enter is equivalent to clicking the "OK" button. Very handy.
2. You can link to an equation by putting it after a pound sign following the URL. So if you wanted to help your friend solve, say, 2+2, you could point them to calc5.com/#2+2. Your friend will still have to click on the "OK" button (I hope this changes soon), but it works. First person to send me a Calc5 link for the Valenzetti Equation gets a free trip on Oceanic Airlines.

Calc5 is fairly powerful, especially with those graphing features, but it's clearly still very beta. Once they get some real documentation in there and some more convenience features, it could become indispensable. For now I'll probably stick to Google Calculator for the easy stuff, and Instacalc for the more complex stuff--unless I need to do some advanced graphing.