[isabelle-dev] Towards the next Isabelle release

Makarius makarius at sketis.net
Tue Jun 8 15:56:23 CEST 2010

On Tue, 8 Jun 2010, Brian Huffman wrote:

> On Tue, Jun 8, 2010 at 3:12 AM, Makarius <makarius at sketis.net> wrote:
>> The current status is as follows:
>>  * isatest refers to http://isabelle.in.tum.de/repos/isabelle-release
>>    until final shipment of Isabelle2009-2
> Why the name "Isabelle2009-2" ? I expected "Isabelle2010" -- the
> current year is 2010, after all.
> Or will the year-part of the name only be incremented for "major" 
> changes?

Yes, this follows established traditions of the glorious history of 
Isabelle, see also 

Some years ago this principle had been almost forgotten, and there was a 
tendency to have exactly one release per year.  This forced artificial 
calendaric constraints on the development process, ultimately resulting in 
the release desaster of 2006. The problem is that is becomes increasingly 
difficult to recover a stable state the longer the distance to the last 
one gets.

This time we are relatively early after Isabelle2009-1, because many 
internal changes (and incompatibilities) have accumulated in the past few 
months.  Little of this can be advertized to end users as big things, 
though.  It is mostly the absence of "features" like non-authentic syntax 
or global-only type specifications that will improve user experience 
without further notice.

When looking through the NEWS and CONTRIBUTORS I've found it hard to pin 
down some notable things to be advertized, despite the hard work that went 
into things mentioned in one sentence here or there (such as proof terms 
for type classes).


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