Google's new Web browser eventually will support add-ons and user scripts à la Firefox Add-ons and Greasemonkey, Google engineer Ojan Vafai said during a panel discussion on the future of Web browsers at Web 2.0 Expo in New York on Friday.

There's two different kinds of add-ons," Vafai said. "The Firefox things extend your browser, so to speak, and then there are user scripts. We intend to do both of those in Google Chrome." Greasemonkey's founder, Aaron Boodman, actually works on the Google Chrome team.

Google Chrome was released earlier this month and saw almost 2 million downloads in the first week alone, raising the visibility of Chrome as a strong new competitor toMozilla Firefox and Microsoft (NSDQ: MSFT) Internet Explorer. It does a number of things differently from either, such as isolating browser tabs so that each one is treated almost like a separate instance of the browser for reliability purposes.

Vafai cautioned that Google will work hard to make sure its add-on paradigm keeps Chrome stable. "We hope to do them right," he said. "As many people notice in Firefox add-ones, there are problems with instability."

There have been some suggestions that Google was looking to eventually take on Windows with Chrome, but Vafai pooh-poohed that notion. "It's apples and oranges, comparing an operating system and a Web browser," he said. "They're in the end, two totally different things. There's a bunch of stuff built into Web browsers that are OS dependent, like font rendering. It's not even clear what it means to replace the OS with the browser."

Mozilla CTO Brendan Eich, joining the panel along with Vafai and Microsoft Internet Explorer platformarchitect Chris Wilson, said that Mozilla was looking at how Google treated tabs as a potential way to improve stability when dealing with browser add-ons. "There are good process-isolation tricks that Chrome does that we're looking into, so we're simply going to look at better isolation techniques for security and integrity," he said.

For Microsoft's part, Wilson noted that though Internet Explorer has long supported add-ons, they can "be challenging to write today." He said he'd like to make the add-on environment better for IE, but didn't give many details. He also questioned the use of user scripts as a privacy risk for typical users who aren't technically proficient.

Wilson, Eich, and Vafai all lent their support to the continued development of Web standards like HTML 5 and CSS 2.1, and pointed to features in those standards that each of their browsers support. This is especially a change of pace for Microsoft, which has until Internet Explorer 8 often resisted supporting some emerging Web standards in deference to backward compatibility.

One standard Microsoft isn't supporting in IE8 is a vector standard called Canvas in HTML 5. Earlier this year, then-Mozilla exec Mike Schroepfer criticized Microsoft's lack of support for Canvas, alleging that Microsoft was instead propping up support for its own proprietary technology in Silverlight. However, Wilson may have put that notion to rest, as he said Friday that "vector graphics support is the next thing we need to work on" in Internet Explorer. Wilson also said that future versions of Internet Explorer would also likely support geo-location, and he said other browsers likely will support it as well.