OpenOffice.org 1.0 provides users with a near-identical software package to Microsoft Office, featuring word processor, spreadsheet and presentation programs.
The source code from the previous release, StarOffice 5.2, was the code base for both OpenOffice.org 1.0 and StarOffice 6.0, but the two products are both advances over that version.
The StarOffice 5.2 software was distributed as a free download before the release of 6.0. Sun's desire to capture business customers led it to offer paid support contracts for 6.0, and still allow free downloads of an improved release, OpenOffice.org 1.0, for users who did not need support or training.
StarOffice 6.0, announced in March and slated for availability this month, comes with additional features such as a database and special fonts. Sun also provides training for StarOffice, which will cost less than $100 (£68).
E-mail and calendar functions disliked by users of StarOffice 5.2 have been removed from OpenOffice.org 1.0, said Zaheda Bhorat, a community manager for OpenOffice.org and a marketing manager for Sun. Future releases will add those functions back in when the community agrees on the best way to do it.
The product also contains support for XML (Extensible Markup Language), which will allow users to save files to PDAs (personal digital assistants) and other mobile devices when plug-ins for that type of file transfer are completed, said Sam Hiser, co-leader of the marketing project at OpenOffice.org and chief information officer of New York startup ReelAmerica.
Users running Linux, Windows, Solaris, and other Unix flavours will be able to run OpenOffice.org 1.0. A port for Macintosh users is in the works, said Bhorat.
The software also was set up to work with several different file formats so that Microsoft Word and Excel files could be kept and worked with in the new version. However, macros and other specially created programs for the Microsoft products will not work with OpenOffice.org 1.0, Hiser said.
Schools, public sector organisations, and companies in developing countries are among the targets of OpenOffice.org 1.0, Hiser said.
"[The software] is a natural companion to Linux," and organisations can significantly cut IT budgets through installing free products like OpenOffice.org 1.0 on their networks, he said.
The software is available in English, but versions in other languages will be released over the next few days.