Dennis,

>Wouldn't that suffer the same consequence as using the RichText control? Over time, the editbox contents will reach its 'overflow' point. The app processes around 12,000 requests (and consequently the same number of logs) PER HOUR.

I'd either

1) only keep the most recent N transactions. You can do this by adding text to the beginning and only keeping the left(,N*transaction width) characters

2) use a grid and put each transaction as a row in a table.

>What do you mean by a browser window? As in web browser control?

Yes, but that too seems impractical with the amount of data you are wanting to show.