In 2013, we had 6 iText releases, numbered from iText 5.4.0 to 5.4.5. For the first release of 2014, we thought it would be a good idea to switch to iText 5.5.0. That way, we get an idea of the release year, just by looking at the number. But let's take a look at what's more important: what's new in this release?
We received plenty of feedback regarding the accessibility functionality that was introduced last year. The PDF/UA spec is relatively new and the ISO committee is still fixing a couple of issues that were discovered in the first version. The same goes for iText.
We've also released XML Worker, iText RUPS and XFA Worker (the latter is a closed source project).