Data, Languages and Systems Interoperability: The Open Source Gallery Explained

The Data, Languages and Systems Interoperability gallery was one of four project galleries of the Outercurve Foundation, a non-profit founded in 2009 as the CodePlex Foundation. The foundation filed articles of dissolution in April 2017, so the gallery no longer operates. Its theme is now handled mostly through open standards.

What was the Data, Languages and Systems Interoperability gallery?

It was a themed project gallery inside the Outercurve Foundation, named for interoperability across data, programming languages and systems. According to Wikipedia's article on the foundation, Outercurve organized its work into four galleries:

• ASP.NET Open Source Gallery
• Research Accelerators
• Data, Languages and Systems Interoperability Gallery
• Innovators Gallery

Interoperability is the ability of different software systems to exchange data and work together. Giving it a gallery of its own made it a named strand of the foundation's portfolio, next to ASP.NET projects, research tools and independent innovators.

The foundation was a 501(c)(6) non-profit that Wikipedia describes as founded by Microsoft and led mostly by Microsoft employees and affiliates. Its stated goal was to "enable the exchange of code and understanding among software companies and open source communities." The gallery's theme matched that goal almost word for word.

How did CodePlex lead to Outercurve?

The gallery came out of a rebranding. The foundation began as the CodePlex Foundation, and the name changed within its first year:

• 10 September 2009: the foundation was founded as the CodePlex Foundation.
• September 2010: it adopted the name Outercurve Foundation.
• November 2010: the bylaws were changed and the board was expanded.
• 12 November 2014: the .NET Foundation announced a new governance model, the post Wikipedia cites for the project transfers described below.
• 22 April 2017: its directors filed articles of dissolution with the Washington Secretary of State.

The early years were not easy. Wikipedia reports that parts of the free software community considered the site subversive and suspected Microsoft of wanting to make people dependent on Windows and its other software. For the hosting side of the story, see how CodePlex hosting worked; for the organizational side, read the account of the move from CodePlex to Outercurve.

Which Outercurve projects are still in use?

Three projects that Outercurve hosted were contributed to the .NET Foundation and continue there, according to Wikipedia:

Project	What it is	Where it went
NuGet	Package manager for .NET libraries	Contributed to the .NET Foundation; Wikipedia does not name its gallery
Kudu	Deployment engine behind Azure web apps	Contributed to the .NET Foundation; gallery not named
ASP.NET AJAX library	Client-side JavaScript library	Contributed to the .NET Foundation; gallery not named

NuGet is the one a .NET build touches whenever it restores packages; NuGet and its contribution covers it in detail.

Why did it matter for open source?

It mattered because the foundation was a non-profit home where code could be exchanged between a large vendor and open source communities, which was its stated goal. NuGet, Kudu and the ASP.NET AJAX library were later contributed to the .NET Foundation, whose new governance model was announced on 12 November 2014. The historic impact of Outercurve and CodePlex traces how far that idea traveled after 2017.

How is interoperability handled today with open standards?

Today, interoperability rests mainly on open standards and documented APIs. An open standard is a specification that is openly accessible and usable by anyone. Under the ITU-T definition, endorsed in November 2005, an open standard meets criteria that include:

• a collaborative, consensus-driven process;
• balance, so that no single interest group dominates;
• essential patents licensed to all applicants on a non-discriminatory basis;
• enough detail to allow competing interoperable implementations;
• public availability at a reasonable price and long-term maintenance.

Several formats and specifications show the idea in practice:

• JSON: RFC 8259, published in December 2017, defines it as a "lightweight, text-based, language-independent data interchange format." It replaced RFC 7159, requires UTF-8 for JSON exchanged between systems, and registers the application/json media type. ECMA-404 describes the same grammar.
• OpenAPI: the OpenAPI Specification describes HTTP APIs in YAML or JSON without tying them to a language. One description file can drive API gateways, server code generation, developer portals, SDKs in several languages and contract tests.
• OpenDocument Format: developed by OASIS and approved by ISO as ISO/IEC 26300 for documents, spreadsheets and presentations. Microsoft's Office Open XML was approved as ISO/IEC 29500, though Wikipedia notes that its openness is contested.
• Web protocols: HTTP, HTML and CSS from the W3C, and TCP and IP from the IETF (RFC 793 and RFC 791), are the long-standing examples.

In August 2012, IEEE, ISOC, W3C, the IETF and the IAB jointly affirmed the OpenStand principles of cooperation, due process, availability and voluntary adoption. The IETF published the declaration as RFC 6852 in January 2013.

The common thread is a contract that does not belong to one vendor, so teams on different languages and platforms exchange data without custom adapters. Licensing still shapes what you can reuse; a guide to choosing a license covers the main options in general terms, not as legal advice.

FAQ

What was the Outercurve Foundation?

A non-profit founded on 10 September 2009 as the CodePlex Foundation and renamed Outercurve in September 2010. It hosted open source projects in four thematic galleries until its dissolution filing in April 2017.

What was the interoperability gallery?

One of Outercurve's four galleries, dedicated to open source work on interoperability across data, languages and systems.

Is the gallery still active?

No. The foundation filed articles of dissolution on 22 April 2017, and some of its best-known projects, such as NuGet, were contributed to the .NET Foundation, under a governance model announced in November 2014.

How do teams achieve interoperability today?

Mostly through open standards such as JSON and OpenAPI, documented APIs and open source licenses that allow reuse.

Sources

• Wikipedia, "Outercurve Foundation" (dates, gallery names, community reaction, projects contributed to the .NET Foundation).
• Wikipedia, "Open standard" (ITU-T criteria, ISO/IEC 26300 and 29500, OpenStand principles).
• OpenAPI Initiative, "What is OpenAPI?".
• IETF, RFC 8259, "The JavaScript Object Notation (JSON) Data Interchange Format".