I hope you find TreeView's charts fast, intuitive and easy to use. Most things that you see will do something sensible if you hover over, or click them. So just hover and click, hover and click, and all should become clear. If you insist on instructions, read on.
The charts will usually open in chart view, anchored on either a person, or a family. To see more information about a person, hover over the person's name. To see more information about a family (including the parents' marriage), hover over the image of the ring that connects the two parents. Clicking on a person will re-draw the chart, anchored on that person. Clicking on a ring will re-draw the chart, anchored on that family.
In the top left of the chart, you'll see three (or four) symbols, a plus sign, a minus sign, a capital "N", and (on some charts only), a capital "C". Click on the plus sign to zoom in, or the minus sign to zoom out. When zoomed in, you'll see fewer generations, but in a bigger font. Click on the capital "N" to bring up an index of surnames; in the surname index, click on a surname to list all the people in the tree with that surname; click on a person to draw that person's chart. The "C", if present, will bring up another browser window showing the web card for the current person or family.
In chart view, you'll see that most people have a "D" (for Descendants) and/or "A" (for Ancestors, or Ahnentafel) next to their names. Clicking on the "D" will bring up a simple list of that person's descendants. Clicking on the "A" will bring up a list of that person's ancestors as an ahnentafel report. If you're not familiar with the layout of ahnentafel reports, all you need to know is the numbering system. The root person is numbered 1; the number of a person's father is obtained by doubling the child's number; add 1 to the father's number to get the mother's number. This scheme makes the ahnentafel report extremely compact. In either report, clicking on a person will bring up that person's chart.
Do not use your browser's back button, unless you really want to leave the chart altogether. You don't need it, as you're never (well, almost never) more than a click away from the last thing you were looking at. Instead, use one of the links in the breadcrumbs trail, beneath the tree's title.
TreeView has been tested on several important browsers, including Firefox (versions 2 and 3), Safari, Chrome, and Internet Explorer (versions 7 and 8). The last has given me the most trouble, and I wish it would go away.
No doubt sooner or later I'll encounter a tree which is too big for this approach, but I haven't yet. The largest tree I've dealt with so far has about 2000 people, and this presents no problems at all for modern browsers, even on my wife's eight-year-old PC.
However, just because it's open source, don't assume that it's also free or open license. It's not. For the time being at least, I reserve all copyright and other intellectual property rights; I grant no license for any use except in my own Web site; and no warranty is implied (if your computer screen explodes in your face while browsing my web site, don't sue me). If you copy, steal, re-distribute or use TreeView in any way without my express written consent, make sure you're not worth suing. And whatever you do, don't link to my treeview.js; stealing bandwidth as well as software is no way to make friends (and it mightn't work, anyway).
This is because I still maintain the fantasy that someone might like TreeView enough to offer me some actual money for it. If you have a product or site that would be better for TreeView, and you want a license, please contact me; I'm also willing to consider commisions. Even if your Web site or software product is free and you have no business model or revenue stream, I may still be willing to grant a license for the greater good. But you need to ask.
So how do you contact me? A determined sleuth will find a way. Clue: where would you expect to find copyright and license statements in an open source program?