Ecma Common Language Infrastructure (CLI) Standard - Working Draft

In August, 2000, the specification for the Common Language Infrastructure (CLI) was submitted to the international standardization organization Ecma. As a result, Ecma formed a task group (TG3) within TC39 (now moved to TC49), its technical committee responsible for programming languages and application development. This specification became known as Ecma-335.

Since the initial submission, various Ecma member companies and individual contributors have produced two editions of the CLI standard, one in 2002 and one in 2006. Each Ecma edition was also submitted and approved by the International Standards Organization (ISO), specifically ISO/IEC JTC 1. The Ecma CLI specification went through the ISO/IEC JTC 1 Fast-Track process and the resulting document is referred to as ISO/IEC 23271. Because Ecma adopts the equivalent ISO document as another edition, the Ecma-335 CLI standard is officially at its 4th edition as of June 2006.

A differently formatted version of each of these documents is being produced for final publication as

  1. ISO/IEC standards and TR (1st edition). To monitor the progress of the publications, please visit
  2. ECMA standards and TR (2nd edition). To monitor the progress of the publications, please visit

Work on the 5th edition of Ecma-335 CLI standard began in mid-2009. The TC49-TG3 task group is working on extending both the virtual machine and class libraries of the CLI specification. In addition, improvements are being made to clarify existing elements of the specification. Many of these improvements are the result of feedback received from outside the task group, for which the task group is grateful.

Posted below is a snapshot of the committee’s work as of 27 March 2010. The participants in TC49/TG3 are providing these working documents to the public for informational purposes only. The contents are subject to change as often as once a month. To participate in the standardization process, contact your organization's Ecma representative. If your company does not currently participate in Ecma and wishes to do so, please contact ECMA ( directly.

The following organizations and contributors are actively participating in the work of TC49/TG3:

Eiffel Software, Microsoft Corporation, Novell Corporation, Kahu Research, and Twin Roots.

The following organizations have previously participated in the work of TC49/TG3 and their contributions are gratefully acknowledged:

Fujitsu Software, Hewlett-Packard, Intel Corporation, International Business Machines, ISE, Monash University, Netscape, OpenWave, Plum Hall, Sun Microsystems.

Many of the organizations that are currently participating in the TC49/TG3 work have volunteered to mirror this site. The URLs for the mirror sites are:

Available Documents (Documents current as of 27 March 2010) The following working draft documents are available: