It was released a month before its companion Thunderbird.
The Gran Paradiso version of this software set a record for most downloaded software in a 24-hour period. A newer version of it uses TraceMonkey and adds support for the "video" tag, and unlike a Trident-using competitor, it uses the Gecko layout engine. This program contains an embedded spell-checker and scores 93/100 on the Acid3 test, lacking support for SVG fonts. ColorZilla and ChatZilla are two of its "add-ons," and smart keywords can be typed in its address bar. It was released a month before its companion Thunderbird. For 10 points, name this open-source web browser, second in popularity to Microsoft's Internet Explorer.
The Gran Paradiso version of this software set a record for most downloaded software in a 24-hour period.
Mozilla {Firefox} [prompt on "Mozilla"]