Yes, Esri's ArcGIS Online is Section 508 compliant.
Here in the U.S. we currently have to comply with Section 508 of the Rehabilitation Act of 1973, as amended which defines, electronic and information technology (EIT) and established the Architectural and Transportation Barriers Compliance Board (Access Board)--under Section 502 of the Rehabilitation Act (29 U.S.C. 792). The "Access Board" establishes standards set forth a definition of EIT and the technical and functional performance criteria necessary for accessibility for EIT. The standards are codified at 36 CFR part 1194
This is changing, and for the past couple of years the U.S. Access-Board ( http://www.access-board.gov/508.htm ) is replacing its Accessibility requirements. It has now published a second advanced draft of "Information Communications Technology (ICT) Standards & Guidelines". Accessibility for "documents" is now to be drawn from the WCAG 2.0 guidelines.
Here is a link to the new draft regulation--http://www.access-board.gov/attachments/article/1702/ict-proposed-rule.pdf
you'll find it is similar to provisions of the European Standard EN 301 549 in implementation of WCAG 2.0.
In the EU--the European Commision (EC) Mandate M 376 Draft European Standard (EN) 301 549 follows modified WCAG 2.0 guidelines for "documents". The current draft EN is found at this link:
For now, software developers and vendors seeking to use U.S. Federal procurement channels prepare a Voluntary Product Accessibility Template (VPAT) form, and independently report their compliance with 36 CFR 1194.21 -- Software Application and Operating Systems -- derived from WCAG 1.0 (1999)
Esri like most Software vendors prepares VPAT (Voluntary Product Accessibility Templates) to comply with provisions of U.S. Code.
The VPAT for ArcGIS Online is here:
or for ArcGIS for Desktop is here:
VPAT for other products are at this Esri hosted website: Legal Information | Voluntary Product Accessibility Templates (VPATs) | Software
You can email specific questions regards Esri's compliance with U.S., EU and other similar regulations to Section508@esri.com
Message was edited by: V Stuart Foote, adjusted the link to the access boards proposed rule