On Tuesday, Adobe is expected to announce the donation in conjunction with the Web 2.0 Conference in San Francisco. The code will form the basis for a new open-source project called Tamarin, which will be governed and manned by developers from Adobe and Mozilla.
Adobe will provide the same software, called the ActionScript Virtual Machine, which it uses to run script code in the Adobe Flash Player 9.
This virtual machine is expected to be built into future versions of the Firefox browser by the first half of 2008, said Frank Hecker, the executive director of the Mozilla Foundation.
The latest version of Adobe's script "engine", released in June this year with Flash Player 9, uses a just-in-time compiler to run programs 10 times faster than previous versions, he said.
Lynch said the deal with Mozilla is the biggest Adobe has done with open source. The move furthers the company's plan to allow developers to mix and match programming technologies, including Ajax-style web development and Flash for media and animation, he said.
"We can bring together the broader HTML and Flash developer communities around this common language implementation," Lynch said. "Using the same language engine is a huge step."