please be so kind to provide more information on future questions - a majority of people here are not from the US and may not know that you refer to Section 508 which requires accessibility compliance for IT systems for federal agencies.
As far as Alfresco compliance is concerned, it would be best for a sales rep or local partner to answer this. Alfresco has certainly included standard-based accessibility features in most of the Share UI, but since I am not familiar with the law myself, I can't say if it would be considered compliant.
