Question

Has anyone seen a recent (and fairly balanced) study into the relative costs for software development using differing languages ? I would particular like to see the relative costs of Java Vs. C# Vs. Delphi.

Answer 1

Quantitative comparisons of this sort would be very hard to pin down, due to the number of complicating variables: developers’ experience with the language, suitability of the language to the target domain, developers’ overall quality (it’s been argued that non-mainstream languages attract higher quality developers), tradeoffs with the resulting product (is a Ruby or Python app as fast as a well-written Delphi or C++ app?), etc.

In Code Complete, 2nd Ed., Steve McConnell lists several languages in terms of their expressive power (how many lines of equivalent C code can be expressed in a single statement of each language). It’s been suggested that programmers’ productivity in lines of code is relatively constant regardless of language; if this is true, then the expressive power of each language should give a rough estimate of the relative cost of development in each language. From Table 4.1, page 62:

LANGUAGE       LEVEL RELATIVE TO C
C              1
C++            2.5
Fortran 95     2
Java           2.5
Perl           6
Python         6
Smalltalk      6
Visual Basic   4.5

He lists several sources for this table: Estimating Software Costs, Software Cost Estimation with Cocomo II, and “An Empirical Comparison of Seven Programming Languages” (by Prechelt, from IEEE Computer, October 2000).

The figures that McConnell cites are all several years old, but from what I understand, the Cocomo II model is ridiculously detailed, so current Cocomo II material may offer current numbers on Delphi and C#.