It's the forth major release since SpamAssassin joined the Apache project in 2003 and the first major update since 2007.
"Apache SpamAssassin is the leading open source email spam filtering software package that is in use by national, regional and local ISPs, email service providers, Fortune Global 500 companies, small to enterprise businesses, all levels of the education sector, governments and private individuals," said Daryl C. W. O'Shea, Chair of the Apache SpamAssassin Project Management Committee and Information Technology Coordinator at the Township of Tay in Ontario, Canada.
According to the press release, "Apache SpamAssassin 3.3.0 represents a major shift in how SpamAssassin rules (the actual patterns that help to identify spam) are updated. Starting with version 3.3.0, rules are now separate from the core product and are instead downloaded using 'sa-update,' SpamAssassin's automatic update software. This method was optional with the 3.2.x series of releases and has proven to be very popular."