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OPeNDAP Software

On this page you will find background information about the software we have available for download. This information includes the public key we use to sign our software, access to the complete archive and information for software developers who use our toolkits about our open software revision system. We manage several different open-source software packages and you can download either source code or pre-built binaries from here. These packages have their own pages that you can access using the links at the left. Package that have their own pages are:

Our modular data server.
Software development toolkit that can be used to build clients and servers using C++.
Other Software
If you don't see what you are after here, contact us at

Note that we also maintain a list of Software developed by other groups that can read from OPeNDAP servers and that there are several other groups that make servers besides us.

OPeNDAP's Public Key

OPeNDAP's Public Key is available here. We now (November 2007) sign all of our software releases using gpg and a key created just for this purpose. The public key is bound to the email address security at The address is 'real' in the sense that email sent there will be answered, although we ask that support questions be sent to the support at address instead. To verify a particular software package using its digital signature:

  • Import the security at public key into your key ring (see the gpg documentation for help on that);
  • Download both the package and the .sig signature file and put them in the same directory; and
  • Run gpg --verify <signature file name> in the directory with those files.

The result should be a message telling you that the signature is valid, who signed it and when it was signed. If you don't get a message saying the signature is valid, double check that you have installed the public key correctly, have the file and its signature in the same directory and have not renamed the file (or signature). If, after that, you're still not getting a message that the signature is valid, please contact us.

Software Archive

The HTTP archive holds just about every piece of software we have ever released. Each release is held in a separate directory. Beta and final versions for each release are within those directories. Below are shortcuts to specific parts of the archive for people that want all of the source code without navigating through the pages specific to each of the clients, servers, et cetera.

Current Releases
Source, Binary, ODC.
Old DODS releases
By Release

Nightly Builds

We run a suite of builds every night. Each nightly build is created using code checked out from SVN. Mostly we use the nightly build process on our current release, although some other software, such as the current development code, is also built. You can see the status of the most recent nightly build, although we do not run nightly builds on all of our platforms.

Subversion (SVN)

Another way to get source code is to use anonymous access to our SVN repository. In Spring of 2005 we switched from CVS to SVN. Our CVS repository required a login for read access as well as write access. Our SVN repository provides public read-only access without a password or login. You'll need an account for write-enabled access; email webmaster at for more information. There are several ways that you can get software using svn.

  • You can use a web browser; visit the URL This is a good way to read over source code if you have specific questions about how a particular function has been implemented. Note that we're currently reorganizing the sources so there is some duplication in the repository. Email opendap-tech if you have questions about what's under active development and what's not.
  • You can use a web browser to view our Trac web site, which provides a browser-based interface to our svn repository.
  • You can use a variety of subversion clients to read from the repository. Generally, you will want to check out source code from the repository's 'trunk' using the URL "" There are many subversion clients available and many plugins for IDEs.

Where to find specific software in the repository

There are many projects in our subversion repository, here are some:

  • libdap: The C++ DAP2 library.
  • Java-OPeNDAP: The Java DAP library for both clients and Servers. This is use by both the netcdf-java library and the TDS (both from Unidata)
  • OC: A pure C implementation of DAP for clients. Used by the netcdf C library.