Used to be an avid Tcler in the early noughties, but later moved on to other pursuits. In 2010, he came back briefly to clean up some useless old pages he'd left behind. He thought that one would be his last editing visit, but in 2013 his youngest son chose (on PL's suggestion) to use Tcl/Tk for the GUI of an encrypting messaging application. PL decided then and there to brush up on his Tcling skills*.
Some pages he made during his first stay:
He certainly didn't create the Endekalogue but seems to have been the first one to use the term.
One of his finest Tcl moments in the 2001-2005 era was when he used Tcl + Tcllib's csv module to save the largest (amateur, possibly overall) database of folk music in Sweden (>100k songs). The collector was using an old database custom-written in Turbo Pascal. All sources and specifications were lost, and as the computers were beginning to go decrepit, he was about to lose years of work. Enter PL with the Tcl CD he used to always carry around. He wrote a probe to find out the database format as the collector was watching, then wrote a dumper to translate it into a CSV file, and then successfully imported it into Access. Programming is always fun; if you can save someone's bacon while programming it's even better.
He started his programming career in the 1980s at Volvo Komponenter (currently Volvo Powertrain) where he used AUTOLisp and Pascal, and later (pre-ANSI) C. He stayed with C and C++ for many years (eventually teaching those languages in secondary school) before a brief but passionate fling with various scripting languages, notably Perl. After working far too hard for too many years, the almost effortless nature of Tcl programming came as a great relief, but unfortunately he couldn't find a way to go professional with Tcl**, so it petered out. In 2013, he found himself working with data extraction/presentation and light systems development, mostly using IBM Cognos Report Studio and VBA for Excel/Access (he was unable to choose his tools at this workplace).
*) "Get a string for a file name consisting of a time stamp? Um, I think you need a command called... 'clock'. *does web search* Yeah, that's it."
**) And to be honest, he was being a bit lax with Tcl use. It shows in places if you look at his code on this wiki.