Here are some opinions and facts about a selection of programming languages by Dr Mark Utting (a lecturer in the Department of Computer Science at The University of Waikato).
The Open Directory Project has lots of programming language information.
For examples of programming in 200+ different languages, check out Tim Robinson's 99 Bottles of Beer page. The Dylan version is nice, but make sure you check out all the C++ versions too! The template version is amazing!
More programming language comparisons, including employer demand, are available at http://www.pixeldate.com/dev/comparison/
One of my favourite object-oriented languages is Cecil, by Craig Chambers. It is a multiple-dispatch language that supports both exploratory untyped programming and large-scale statically-typed programming. It includes some new and very expressive ideas (see the paper "Predicate Dispatching: A Unified Theory of Dispatch" by Michael Ernst, Craig Kaplan and Craig Chambers). Cecil is quite similar to the theoretical language that I developed in my PhD thesis.
An equally nice language is Dylan. Like Cecil, Dylan is a safe, strongly-typed, pure object-oriented language that supports multiple dispatch, modules, first-class functions etc. Dylan was originally designed by Andrew Shalit at Apple. There is a commercial implementation of it for Windows 95/NT platforms available from Functional Objects Inc., with a personal version available via free download. Free versions of Dylan for various UNIX machines are available from the Gywdion group. Other useful Dylan sites include:
Python is another favourite. Interpreted, and ideal for knocking up quick prototypes, but with a nice module system, lots of handy libraries, and almost purely object-oriented.
Apart from Simula-67, Smalltalk started the OO craze. Implementations are becoming more easily available now. (See also ObjectShare's non-commercial VisualWorks Smalltalk, available for Linux and Windows) Squeak is an open source Smalltalk that is becoming very popular. A lot of Smalltalk-related information and projects are accessible from the Panasoft Smalltalk Links. Here is a nice Smalltalk tutorial from IBM.
Some other clean OOLs are:
Then we have the less clean C extensions: Objective-C seems less widely used now, but is supported by gcc.
C++ is the most
widely used object-oriented language. See: Readings, FAQS, ANSI Standard or here
A recommended book on
the design of C++ is
"The Design and Evolution of C++", by Bjarne Stroustrup, Addison-Wesley, 1995.
I quite like the standard template library (STL) of C++ (local docs here). It allows higher-order programming to a certain extent and comes with about 10 generic data structures and 70 simple algorithms over them. See Mumit's STL Newbie guide for some handy STL hints. Other STL-like libraries include: the Graph Template Library (GTL).
There seem to be two major contenders for the "best GUI toolkit" title at the moment. GTK+ (the GIMP toolkit) is more C oriented, but does slots and signals without a preprocessor, whereas Qt uses a preprocessor (MOC) but has the dis/advantage of being a complete solution for porting to Windows 95/NT. The GTK+ toolkit has bindings for several languages, including a C++ wrapper for GTK+ called gtk-- (or FTP).
Of course, there is the cleaner C++ derivative, Java (see also the Java white paper, a Java tutorial, Java Games and Java Puzzles).
The two most attractive aspects of Java are that it can be a safe language (all errors are caught by the compiler or bytecode checker or cause runtime exceptions), and its portability (especially its wide range of standard libraries).
Some problems with Java that I've heard about include: hard to format a floating point number, integers etc. are not objects so cannot be subtyped or subranged, non-portable thread semantics, text I/O difficult for beginners. The lack of generics is a real pain in Java (lots of type casting), but the upcoming Java 1.5 will fix this at last.
Here are several interesting extensions/variants of Java:
Even Ada and Perl (Perl 4 was my least-liked language!) are object-oriented these days.
Rational Software Corporation have done an interesting comparison between development in C and Ada.
Rational Software Corporation also sell Purify (a heap-memory checker) and are responsible for the OO Unified Modelling Language, which is now the industry standard for specifying the structure of OO systems.
Finally, CLU is an old but influential language that introduced important ideas for iterating through collection objects, for exception handling and a carefully-designed theory of object invariants, pre/post conditions etc.
Here are some Software Engineering methods/tools for object-oriented programming:
It is not too hard to interface Haskell to arbitrary C procedures, and I have interfaced it to mSQL (a freely available mini-SQL database system). Contact me for details.
I am part of the Starlog research group, which is designing and implementing a new pure logic-programming language that is especially suited to reactive and real-time programming. Recently, I've implemented a version of Starlog for controlling Lego Robots!
Prolog is the most commonly known logic programming language, albeit impure. A few well-known implementations are: Quintus Prolog, SICStus Prolog, Eclipse Prolog, SWI Prolog (free!). Qu-Prolog is Prolog customised for formal methods (it handles quantifiers, object-variables and substitutions as primitives).
The Prolog at VIP is free for non-commercial use. Another free one is TRINC-Prolog. Michael D. Kersey recommends Amzi! Logic Explorer and the "Adventures in Prolog" (with a "very nice and complete tutorial"). See here for other free Prologs. [mindgap@my-dejanews.com, Alexander.Apostolovski@worldonline.be, and mkersey@metricom.com; comp.lang.prolog, 12Mar99.]
Roman Bartak's Interactive Prolog Guide includes FAQs, program samples, implementations, and references.
The BURKS project provides documentation and free Prolog implementations for DOS, Windows etc.
LPA Prolog for Windows -- with an IDE and single-step debugger -- offers a free 30-day trial. [Nov98]
Amzi! Logic Explorer is free for personal use. It comes with a full tutorial and sample programs, plus a GUI development environment. Amzi! inc. also offers a Prolog compiler and embeddable libraries (for C/C++, Java, Delphi, VB, etc) for a 90-day trial. [Dec98]
Mercury is an elegant, pure, logic programming language from Melbourne University. The fastest logic programming language around...
The Cetus Links OO Prolog page has links to object-oriented logic programming languages. Curry is an extension of Haskell that adds logic-programming features like logical variables, constraint solving and concurrent and distributed programming.
Here are some useful online sites for constraint logic programming:
The quarterly Logic Programming Newsletter is now online.
The textbook Logic, Programming and Prolog (2ed) by Ulf Nilsson and Jan Maluszynski is now available online. It covers theoretical aspects of logic programming as well as practical programming in Prolog, and extensions logic programming such as equational logic programming, constraint logic programming and query answering in deductive databases.
Basser Lout is another text formatting language that produces Postscript/PDF directly and has a more elegant (and functional!) programming/macro language than TeX.
For HTML (the web markup language):
Poplog is an open source, extendable, portable, multilanguage software development environment providing incremental compilers for several interactive programming languages: Pop-11, Prolog, Common Lisp, and Standard ML. It comes with documentation, libraries, and teaching materials for AI and Computer science (and more general programming).