The Bar Code FAQ [L1 ] has valuable information, but is available only in PDF. BarCode1 FAQ [L2 ] is an entirely different document.
ZZZ [L3 ] is a point-of-sale application coded in Tcl.
Archiver [L4 ] is an archival application written in Tcl.
One CueCat decoder [L5 ] is written in Tcl.
"A fully automated high-throughput HPLC-MS system ..." is an academic article which describes a Tcl-coded biochemical system which employs barcodes.
Mads Linden writes, "i dont know if this will help you, but what i did was to download a 3of9 barcode font to my system and then just using that font when sending data to the printer extension from michael swartz.
get the font here: http://www.adams1.com/pub/russadam/fonts.html ex.
gdi text $hdc 50 50 -text "*MYBARCODESTRING*" -font "{3 of 9} 12"
BarCode DataBase [L6 ] is coded in Perl.
GNU Barcode [L7 ] is a command-line executable.
Harald Oehlmann and kroc are in the barcode business.
RS played with Code 39 generation
And PS did the same for EAN-13 generation
There are "barcode printers" which accept textual Zebra Programming Language (ZPL). Tcl is as good at generating ZPL as any likely competitor.
"Barcode Writer in Pure Postscript" [L8 ] is open source.