This is not an answer to your question, but
1) For GNOME, there is Straw, which is not a ticker, but a normal windowing program.
http://www.nongnu.org/straw/
2) If you wanted to write a ticker, you could probably reuse a lot of code from existing apps, like Straw.
3) Firefox 1.0PR supports live bookmarks, which may be more or less preferable than a ticker, depending on your habits.
HTH,
Samsara