After my post on Apache's
Harmony project I have been watching the fireworks on the
blogs and the mailing lists. One thing is clear: nobody quite
knows what Harmony is supposed to be.
There are pros and cons. The main pro is that I discovered
the BileBlog, a
modern-age blog that reads like a good Jamie Zawinski
opinion. In particular the flame about project Harmony is gem.
Unlike Mono, open source Java faces a big problem: there
are a number of free commercial Java runtimes available for
every operating system that matters. The group of people who
would have contributed to a free java to scratch an itch are
gone. From those who remain another large chunk will switch
in a heartbeat to a commercial implementation the moment they
run into missing features, scalability issues, the lack of a
moving GC or a hard to debug problem.
So you must rely purely on free software advocates or
people employed to clone Sun's Java for a strategic purpose.
To illustrate my point: Mark reports
that for the two months leading to May 7th GNU Classpath had
299 commits and today is made up of roughly 900,000 lines of
source code. Mono in the same time frame had 985 commits to
its core class libraries and has roughly of 1,600,000 lines of
code. The previous count is only for the core class libraries
and does not include Mono-specific or Gnome-specific class
libraries. The Mono effort is also three years younger than
Classpath and five years younger than Kaffe.
For an open source Java effort to succeed, it not only
needs to match the functionality of Sun's Java first, but it
must offer functionality that is not available anywhere if it
wants to attract developers to its core. Today there are
probably two openings in this area. IKVM which makes Java and .NET
run side-by-side and GCJ which turns Java code into native
Java and C#, CLI and JVM
Havoc last post
bounces across every possible point.
I was not going to enter the language discussion on
PlanetGnome, because it touches on too many topics. For one,
I think that:
- Some key libraries must remain written in C. And
we (The Mono Group) have a very good framework for
binding GObject-based APIs into Mono APIs.
- We have a tendency to dump things into a library
and hoping that every application will use the library
to gain consistency.
For example, recently a user mailed me to point
out that although he can browse his files on a SMB
share, he can not actually use any of his local tools
to manipulate these files. It turns out that instead
of doing the obvious thing, which was to ask the
kernel to mount the file system the path we went down
on was to use the Gnome-VFS to provide an SMB
transport. And this works beautifully with the Gnome
tools, but it does not work with any other tools.
- Mono right now shines as a platform for developing
desktop applications, and we want to make sure that
the developer experience there is great. Once we have
conquered that space, we can organically reach into
other spaces, but lets first get the first generation
of Mono-based GNOME applications rock solid and
- I would very much like Mono-based applications to
be part of the standard Gnome desktop release and get
the stamp of approval of the Gnome Foundation. There
is no mandate that all distributions must ship all the
packages, so Red Hat can just not ship this.
I think my comments echo Mikael's
post, which both Jeffrey and Havoc seem to have missed.
I wanted to follow up on a few things that Havoc mentioned:
- Graydon's contrast
of Java and C# GUI code is a passable rendering of
Java source code into C#, but is hardly an analysis of
the technical issues.
For an actual technical technical contrast there
C# for Java programmers document and the eight-part interviews
with Anders Hejlsberg.
Last year I was invited to present to the Red Hat Java
summit in Boston. My presentation at the time focused on
teaching to a Java-savvy audience the differences between the
languages Java and C# and the JVM and the CLI, I have uploaded
the slides here.
- The same universe of open source libraries
being furiously developed for Java are being
developed for .NET. Either direct ports, or
re-implementations of the same concepts.
Mind you, a lot of these open source technologies
under development for Java and .NET give me a
Freshmeat.net-deja vu. I still fail to see the
correlation between all this server code and the Gnome
- I can only smile when I see that Havoc tells
people to try Java 5 as an alternative to Mono.
Specially considering that any use of Java 5 features
will likely lock people into using Sun's proprietary