[isabelle-dev] Isabelle DejaVu against old Isabelle Text font

Makarius makarius at sketis.net
Sun Feb 10 19:58:30 CET 2019

On 05/02/2019 20:19, Makarius wrote:
> On 05.02.19 11:43, Peter Lammich wrote:
>> Is this worsening due to another Java version, due to the new Isabelle
>> font, or has it some other reasons? How to find out?
> From a distance, I would say that this is a matter of the Java 11
> font-renderer, which is provided by https://adoptopenjdk.net. The one by
> Oracle is much worse -- OpenJdk not the non-free Java. (Note that the
> license change of non-free Oracle Java no longer allows to bundle it.)

Even more, JDK 11 from Oracle is now distributed as non-free: users have
to pay a subscription to use it in applications. Only some testing and
development is allowed without extra payment. (See

Java 8 is being phased out after Jan-2019. Since the Java community is
notoriously slow in giving up legacy versions, there will be a bit more
time to hold the breath and pretend that nothing has happened.

In contrast, Isabelle is already on Java 11: it performs much better
than Java 8, especially on high-end hardware with many cores
(potentially also on "containers" like Docker). I have already seen some
Isabelle/Scala scalability problems some months ago; luckily this has
been resolved with Java 11.


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