3-Heights™ PDF Validator: Server tool that verifies if a PDF document or an entire archive is PDF/A-compliant. Is available as an API, command line tool, and Windows NT Service.
www.pdf-tools.com

Adobe Acrobat 8 Professional / 9 Pro (Mac OS X/Windows): The ‘Preflight’ function validates PDF/A file versus all the requirements of the Standard ISO 19005. Issues will generate a detailed report which can be saved as PDF or XML.
www.adobe.com

callas pdfaPilot 2: Validates PDF files for their compliance with the PDF/A standard. Available as interactive Desktop product that includes a XMP Extension Schema Editor, as Server, as Command line module and as library. Based on the same callas technology that Adobe uses in Adobe Acrobat.
www.callassoftware.com

ImageGear: ImageGear includes tools for image viewing, compression, scanning, annotation, processing, editing, printing, and more. ImageGear incorporates the latest Adobe PDF library, allowing developers to automatically conform to the highest PDF Language Standard.
www.accusoft.com

OS.5|ECM: This ECM software suite offers complete support of the ISO standard PDF/A. The OS_PDF/A dispatcher module provides the central interface to integrated conversion and validation components from third-party vendors (LuraTech, callas software). Documents from countless original formats can be converted to PDF/A and validated, before they are archived.
www.optimal-systems.de

PDF/A Manager: Validates PDF/A files for compliance with the PDF/A Specification (both PDF/A-1a and PDF/A-1b). Produces a detailed report of compliance violations and a list of relevant error objects. Also includes PDF to PDF/A conversion. Available as a command-line tool or as a development library for integration with 3rd party applications.
www.pdftron.com

SEAL Systems PDF Checker: verifies PDF files for standard conformity to a definite set of rules (eg. PDF/A). PDF Checker is available for batch mode processing or interactive usage.
www.pdfforever.de

SEAL Systems PDF Longlife Suite Integration in SAP PLM: controls nearly all ways for archiving a PDF/A file within SAP. This leads to a standardized data base.
www.pdfforever.de

Solid Documents Solid PDF Tools: Converts existing standard PDFs directly to PDF/A-1b including validation and correction to ensure compliance.
www.soliddocuments.com