Open source TCK was: JDK 9: General Availability

Andrew Haley aph at
Sun Sep 24 06:46:43 UTC 2017

On 24/09/17 00:51, David Herron wrote:
>  You make a compelling case and I largely agree with the goal of "open
> sourcing" the TCK's.  Doing so would go a long way towards truly opening
> the OpenJDK project.
> There is a practical question regarding the primary use for the
> TCK's - which is to certify compliance with the specifications.
> An open source software project is free to be downloaded, modified,
> and the modified version distributed at will.

Not necessarily: there are variants of free licences which don't
permit some sections to be changed.  But it doesn't really matter what
licence is used for the TCK itself: the Java Compatible badge would be
reserved for implementations which had passed TCK Version n.n, as
posted at  That would be the canonical one true TCK.  Sure,
people would be able to hack their own copies of the TCK, but what
would be the point?  The purpose of passing the TCK is to ensure
compatibility with other implementations.  There isn't any motive to
claim compliance with a private version of the TCK.

> For the purpose of sharing of test results, open sourcing the TCK's would
> be great.  The TCK's have a different purpose than just verifying
> functionality.
> Hence, if someone tested with a modified TCK how can there be certainty
> about the result?  Can the results of testing with a modified TCK be
> trusted for certification of compliance?

No, and no.

Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <>
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671

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