Technologies for Development of Distributed Hypermedia Applications
Technologies that apply to Issues in the Development
of Distributed Hypermedia Applications. (with an emphasis on released,
royalty-free technologies). Don't forget to brows
Mobile Code technologies.
Unification -- ILU Evaluation
Nifty work on interfaces between software modules, including
RPC interfaces. Relates DCE and CORBA. Supports C, Modula-3, and there was
some talk about Ada, emacs-lisp, Python, and others. The architecture has
a single interface specification language, plus an extensible set of message
formats (called protocols, of all things, in ILU-terminology), and transports.
For example, an XDR/UDP combo allows interoperability with SunRPC clients
and servers. The CORBA IIOP is supported in version2.0. Xerox courier is
supported via another combination. Calls within the same address space are
also supported. All these combinations can be mixed in the same process,
so that gateways are trivial.
Language support includes C, C++, Modula-3, python, Common Lisp and tcl.
Java is in the works.
Simple Wrapper and Interface Generator. Interesting
Java RMI (and serialization)
serialization == m3 pickle. (with graph traversal). "call by value" objects,
with implementation going over the wire (ala obliq)
(as Java VM implementation)
Modula-3 combines safe programming (ala Lisp) and unsafe programming (ala
C), objects (ala C++), threads, and interfaces (ala Modula-2). It's the most
practical technolgy I've seen for building large distributed applications.
Threads, an M3 newsletter.
This is a nifty object-oriented scripting language. Kinda like Modula-3 meets
perl. See also:
Tcl Doesn't Scale Well
Obliq is a lexically-scoped untyped interpreted language that supports
distributed object-oriented computation.
An Obliq computation may involve multiple threads of control within an address
space, multiple address spaces on a machine, heterogeneous machines over
a local network, and multiple networks over the Internet.
Obliq objects have state and are local to a site. Obliq computations can
roam over the network, while maintaining network connections.
We want to take over the world. The internet badly needs a public
domain software environment that allows the rapid construction of software
tools using a modern programming language. Our goal is to build such a system
using Scheme 48, an ultra-portable Scheme implementation which is easily
interfaced to existing software written in other languages.
Ian Horswill --- email@example.com
See also: my
thoughts on scheme48 for collaborative engineering
OMG COM/CORBA interworking
CORBA interface identifiers are mapped to a reserved portion of the UUID
space using MD5. I suppose we can use that for URLs as well, no?
Q: What happens when you QueryInterface on a CORBA object?
A: 188.8.131.52 CORBA::Composable::query_interface()
primary_interface is just QI on IUnknown(). "C++ style implementation inheritance
is not possible." Bull-pucky. It's not expressible in MIDL, but it's usable
(and useful!) as an implementation technique.
184.108.40.206 is goofy. "Com objects are either initialized empty or arbitrary".
Not true: factories can export creation methods that take arguments. And
the definition of object identity in COM is that QI on IUnknown for all interface
pointers on the same object returns the same thing.
220.127.116.11 makes claims about reference counting in wide area apps. The M3 networked
object Distributed GC algorithm has proven (theoretically and practically)
to work, and it's based on reference counting (as I recall). I know the ILU
network garbage collection strategy is based on reference counting. This
claim doesn't seem to hold water. Their claims about pinging seem to attack
the implementation, rather than the model (whereas they were not willing
to give COM credit for persistence and identity, which do exist, though they
are built to top, and not intrinsic). Hmm... IMonikerProvider seems to bridge
Exception mapping: extra arg. Yuk.
pointer is mapped to a sequence of one arg. Interesting. Sharing? Nope. Causes
Digital Creations is releasing their freely-available
integration of ILU and various
http servers. An infromational W3C draft is available:
ANSA Information Services
Framework Distributed Objects and the World Wide Web
ANSA is building a set of tools to integrate a distributed object model into
WWW. The objective is to provide a CORBA based environment from which the
web appears to consist of a world of distributed CORBA objects.
Web Objects -- Arjuna Group,
Dept. of Computing Science, Newcastle University
of TCL with Orbix (IONA's ORB)
Subject: Re: Q: Tcl CORBA extension
Date: 17 Jul 1995 19:08:56 GMT
Organization: Customer of EUnet Germany; Info: info@Germany.EU.net
GROW -- The GNU Remote Operations Web
@@need to study this
These systems are generally used to build LAN or enterprise distributed database
by NeXT. Includes web interoperability. Lots of O/S's supported.
@@need to investigate further
@@need more info
Combined with MS/Access (and lots of other components known variously as
VBXs, OLE controls, etc) VB is a booming applications development platform.
check out JIDL
UW Cecil Project Home Page
UF/NA Perl Archive
Unification -- ILU
The Scheme Programming
- Table of Contents
Project at SRC Home Page
Programming Language Research
portable posix common runtime. Supports threads, GC over standard posix runtime
Remote file ftp.yggdrasil.com/pub
Linux kernel changes
to the Linux Software Map Broker
to the Linux Software Map Harvest Broker
last update by $Author $ on $Date $