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PERFORMANCE

Cross-platform running times markedly differ. For 2,000 HTML questionnaires of 120 kB each, containing 120 lines (with IDSS definition of a 'line'), 36 variables and a total of 192 characters to be parsed, on a laptop built in 2003, equipped with an Intel Mobile Celeron processor running at 2,4 GHz and 512 MB of  DDR, the following results were obtained on generating a separated database (option -B) :

GNU/Linux Windows XP Cygwin (with Windows XP)
< 20 seconds  of processing time
(minimum 14 seconds out of  20 tests)
20-25 seconds of real time 		 75-85 seconds of  real time > 4 minutes  of  real time


Silent mode -W was used to cut down running times in all tests.
Under GNU/Linux, silent mode running times (options -ir -B -e -s -W) are slightly higher than gzip compression of the questionnaire directory (command 'tar -cf9z'), yet three times lower than copying the same directory from one file system to another ('cp -R') and four times lower than bzip2 compression (command 'tar -cf9j'). These are indicative results, which are likely to depend on hardware configuration. 

Implementing an algorithm written in C limited to the core requirements of survey management made it possible to enhance input parsing performance. Many professional applications take a different approach, implementing general-purpose algorithms (notably regular expressions), whose complex routines allow for more layout flexibility at the expense of higher running times.

Commonly-used interpreted languages boast high-quality libraries for parsing HTML documents (VBA under Windows, Python and Perl in Unix systems) and perform varied tasks; however, IDSS runs faster by an order of magnitude at least.
 
Considering these comparative tests, it is advised to run IDSS under GNU/Linux (or more generally a POSIX standard) to process a large number of questionnaires.