The Mozilla Marketplace for Web apps is locked to outsiders -- for now. (Credit: Screenshot by Seth Rosenblatt/CNET)

Mozilla took a big step toward the coming conflict between native apps and Web apps as it introduced Web app support to Firefox 16, which moved to the the developer's Aurora channel last Friday.

The Web app support in Firefox 16 Aurora (download for Windows, for Mac, for Linux, and for Android) means that when the Mozilla Marketplace opens to the public -- likely to be sometime before the end of 2012 -- people will be able to run Web-based apps through any iteration of Firefox. This is part of Mozilla's "Kilimanjaro" project, syncing up the various Mozilla projects in preparation for the Firefox OS push that's coming next year.

This comes on the heels of the Firefox 15 release to beta, which focused on major improvements to memory management on the desktop version. There's more in Firefox 16 than just Web apps, though. The desktop versions of the browser have turned on VoiceOver support by default for the Mac, and they also have improved the functionality of the built-in PDF reader across all platforms.

For Web developers, Aurora on desktops comes with Opus codec support turned on by default, per tab reporting in about:memory, and a new developer toolbar. Available through the Developer menu or Shift+F2, it offers quick links to developer tools, an error count for the Web Console, and a command line for faster keyboard access.

Firefox 16 Aurora for Android also comes with Web app support, and offers some new features that many competitors already offer. Reader Mode is new in this version, along with a Read Now book icon in the location bar. When you tap the Read Now icon, it'll add the site you're looking at to a "read it later" option called Reading List.

It's also got a new "tab send" feature that emulates the Chrome-to-Phone and Fox-to-Phone add-ons. When you choose Firefox Sync from the Share list, you can send the tab to any of your other computers or devices connected via Firefox Sync. Finally, search suggestions now appear when typing text into the location bar, along with recommendations from your history.

All four cross-platform versions of Firefox now support numerous unprefixed CSS3 features. This means that the Mozilla-specific prefixes for certain CSS3 code, the ones that begin "-moz-border-radius," for example, have been simplified to "-border-radius." A lot of this is about how the next versions of HTML and CSS are made, and what it really means is that the next-generation versions of those coding languages, HTML5 and CSS3, are maturing to a point where they are supported by a wider number of browser makers.

You can read the full changelog for Firefox 16 Aurora here, and Firefox 16 Aurora for Android here. Firefox 16 is expected to reach the wide-release stable version the week of October 8.