EAME: Evolving
Artificial Moral Ecologies
Java Information
- Java is a progamming language descended from C++. It is designed to be
platform independent, and runs within a protected environment in your Web Browser called a
"java virtual machine." This means that it is safe to run Java programs on you
computer, since they are isolated within the "virtual machine" and cannot write
to files, give you viruses, or trash you hard drive.
- Macintosh warning: M
Many complex Java progams do not run well on Macintosh computers, since the virtual
machines available for Mac browsers do not support Java "threads" or multiple
independent processes well. In fact, many of the simulators on this site will crash your
Mac. There are big ugly transition warning pages to accommodate Mac users. So much for
platform independence!
UPDATE 4/6/99: Rumor has it that some of the new Mac
arrangents run multi-threaded applets just fine. I can't tell you which ones,
unfortunatly.
- JDK versions: Java is an evolving language. There have been several
versions of the "Java Development Kit" (JDK) put out by Sun Microsystems. 1.0
was the original. 1.1 is the current version. 1.2 is in now available from sun (they are
also calling it version 2!) There are also sub versions, like 1.1.6. The versions
are supposed to be backward compatible, but older virtual machines will fail to recocgnize
method calls from newer JDK's. So update (the simplest thing is to update your browser).
- Speed: one of the reasons that Java progams are safe on your computer
is that they are actually compiled on your machine after you download the
"bytecode". So your browser gets to check out the code before you run it. This
way of doing things can make for slow going. One solution has been to implement
"just-in-time" (JIT) compiling in the virtual machines. Consequently, browsers
which run later sub-versions of the JDK may run the simulators faster. In a netscape
browser, you can find out what version of the JDK you are running by opening the
"Java Console" on the tools menu (which gets different names).
UPDATE 4/6/99: Internet explorer 5's Java Virtual
Machine seems to run about twice as fast as the netscape version 4 VM.
- Browsers: Netscape and Internet Explorer: Microsoft's Internet Explorer
versions 3 and 4 should run these simulations OK, but Microsoft uses their own
"virtual machines" which seem to lag a bit in implementing the newer JDK's. The
new Netscape browsers seem to run later versions, so that's the best bet for running the
simulations. Caveats: the later versions of browsers are generally bigger and slower to
load, so if you have an old machine you might be stuck with an older browser. (Again,
these simulations run fine on NN and IE versions 3.) Netscape "communicator" is
a big package that includes Navigator and other stuff you may not need. Downloading could
take a while. (30 minutes to an hour by modem.) Installation is easy, though.