DAS/2

The DAS/2 Protocol

About DAS/2

DAS/2 is a more flexible and powerful version of the original DAS/1. The DAS/2 code base consists of:

1. The DAS/2 specification
2. A publically accessible DAS/2 server implementation (open source code available from the GMOD project)
3. An open-source DAS/2 client implementation
4. An open-source client library and server validation suite

DAS/2 History

DAS/2 evolved from DAS/1 through a community-driven process, informed by a variety of RFCs (Requests for Comment) received from the community of users and implementers of the spec. As of November 2006, the retrieval portion of the DAS/2 spec has stabilized. Implementers can rely on this for their DAS/2-based development efforts.

DAS/2 development officially commenced in July 2004 when a 2-year NIH grant was funded. Participating in the DAS/2 grant are Affymetrix, Cold Spring Harbor Lab, the European Bioinformatics Institute/Sanger Center, and Dalke Scientific.

Given that the DAS/2 specification is not backward compatible with the DAS/1 version, existing DAS software will continue to support DAS/1. A DAS proxy server is in development that will permit a DAS/1 server to be accessed by DAS/2 clients.

Clients

The following software packages operate as clients capable of interacting with servers supporting the DAS/2 protocol:

• IGB - Integrated Genome Browser
• GBrowse - Generic Genome Browser

Servers

The following software packages operate as servers capable of providing data in response to queries conforming with the DAS/2 protocol:

• Biopackages DAS/2 server - a DAS/2 reference implementation
• Affymetrix Public DAS/2 server

Publishing and Discovery of DAS/2 sources

See DasRegistry

Global Sequence Identifiers

See GlobalSeqIDs