The links listed below point to websites that carry useful information relating directly or indirectly to PDF/X.
The website of the European Color Initiative (ECI) provides useful information around color management and PDF/X-3: www.eci.org
Stephan Jaeggi, also known as the PDF pope, offers a wealth of down to earth information about PDF and PDF/X. www.prepress.ch
If you believe an essential link is missing on this list, please submit your suggestion to: Email to pdfx.info admin