iText consists of several jars.

The main iText release contains:
- itextpdf-x.y.z.jar: the core library
- itext-xtra-x.y.z.jar: extra functionality (PDF 2!)
- itext-pdfa-x.y.z.jar: PDF/A-related functionality
This project is hosted on http://sourceforge.net/projects/itext/
You can find the latest release here:
http://sourceforge.net/projects/itext/files/iText/

In some cases, you'll need extra jars.
These jars are bundled in a zip file here:
http://sourceforge.net/projects/itext/files/extrajars/

For XML (and HTML) functionality, you need this jar:
- xmlworker-x.y.z.jar
This project is hosted on http://sourceforge.net/projects/xmlworker/

Finally, we also have a tool that can help you debug PDFs:
- itext-rups-x.y.z.jar
This project is hosted on http://sourceforge.net/projects/itextrups/

iText is licensed as AGPL software.
AGPL is a free / open source software license.
This doesn't mean the software is gratis!
Buying a license is mandatory as soon as you develop commercial activities
distributing the iText software inside your product or deploying it on a network
without disclosing the source code of your own applications under the AGPL license.
These activities include: offering paid services to customers as an ASP,
serving PDFs on the fly in the cloud or in a web application,
shipping iText with a closed source product.

Contact sales for more info: http://itextpdf.com/sales