Manifest: Tuesday 4 April 2000

Assignments Due
Tuesday, 11 April (in class)	Problem Set 3
Monday, 17 April (11:59pm)	Position Paper 5
Friday, 28 April	Project Final Report

Read before Thursday 6 April (handed out 23 March):

Luca Cardelli. Basic Polymorphic Typechecking. Science of Computer Programming, 8(2): 147-172, 1987.

Read before or after Tuesday 11 April (handed out today):

Raphael Finkel. Advanced Programming Language Design, "Chapter 7: Concurrent Programming". Addison-Wesley, 1996.

• What is denotational semantics?
• What are the relative advantages and disadvantages of the semantics mechanisms we have seen in this class: operational semantics, static semantics (type judgements), axiomatic semantics, lambda calculus and denotational semantics?
• Which of operational semantics, static semantics (type judgements), axiomatic semantics, lambda calculus or denotational semantics is the best tool for a particular problem.
• How to define a denotational semantics for a simple programming language.
• How to use denotational semantics to prove observational equivalence.

In this case, Microsoft early on recognized middleware as the Trojan horse that, once having, in effect, infiltrated the applications barrier, could enable rival operating systems to enter the market for Intel-compatible PC operating systems unimpeded. Simply put, middleware threatened to demolish Microsoft's coveted monopoly power. Alerted to the threat, Microsoft strove over a period of approximately four years to prevent middleware technologies from fostering the development of enough full-featured, cross-platform applications to erode the application barrier. In pursuit of this goal, Microsoft sought to convince developers to concentrate on Windows-specific APIs and ignore interfaces exposed by the two incantations of middleware that posed the greatest threat, namely, Netscape's Navigator Web browser and Sun's implementation of Java technology. Microsoft's campaign succeeded in preventing - for several years, and perhaps permanently - Navigator and Java from fulfilling their potential to open the market for Intel-compatible PC operating systems to competition on the merits.

From Judge Thomas Penfield Jackson's Conclusions of Law in the Microsoft Anti-Trust Trial, 3 April 2000.

University of Virginia CS 655: Programming Languages

cs655-staff@cs.virginia.edu Last modified: Mon Feb 26 12:48:25 2001