jsforth abstract:

jsforth is a Forth which has been implemented in JavaScript, using a web browser as host platform. Current screen layout works best with screen resolutions of 1024x768 or higher. Firefox, Mozilla, Netscape are the best-supported browsers at this point.

Some jsforth features:

  • interactive terminal emulation
  • blocks file system:
    • client side disk emulation:
      • cookies
      • ram drive
    • server side emulation:
      • remote blocks are loaded dynamically on demand.
  • multi-standard and dialect support
    • jsforth personality can be changed easily. Command to switch to a different standard or Forth dialect are provided.
  • integrated help and tutorial system (under construction)
  • catch/throw exception handling intercepts JavaScript errors too.
  • Rich set of Forth words. Only few words from the ANS core and core ext set haven't been implemented, implementation status documented on ForthCoreWords.

browser issues overview:

problem\browser Moz Fir Nsc Epi Gal Opr7 Opr9 K331 K332 K355 Saf IE5 IE6 Eli Mmo kaze
key input ++ ++ ++ ++(3) ++ ++ ++ -- ++ ++ ++ -- + -- ++ ++
web blocks ++ ++ ++ ++ +++ -- o(2) -- -- -- -- ++ ++
cursor pos ++ ++ ++ ++ ++ - ++ - - - ++ ++ ++
backspace ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ –(1) ++ ++
errorhandler ++ ++ ++ ++ ++ ++ ++ ++ ++ ++ -- ++ ++
#cookies ? 4 ? ? 4 ? ? ? ? ? ? ? 5 (+?)
overall usability ++ ++ ++ ++ ++ - + -- - - - -- -- -- ++ ++ 
(1) IE backspace: use ctrl-q
(2) Opera 9.x web blocks: unreliable. gets wrong blocks sometimes, or none. Opera 10.x doesn't seem to show those problems, and worked well in all respects.
(3) Epiphany versions 2.28.x suffer from a javascript problem. 2.29.1-1 works mostly again, but Esc key is not passed to jsforth
  • Moz: Mozilla 1.7.x
  • Mmo: Minimo Embedded Mozilla
  • Fir: Firefox 1.x - 2.x
  • Nsc: Netscape 7
  • (3)Epi: Epiphany 1.4.7 - 2.26.x, 2.29.1-1
  • Gal: Galeon 1.3.x - 2.0.x
  • Opr7: Opera 7.54
  • Opr9: Opera 9.61
  • K331: Konqueror 3.3.1
  • K332: Konqueror 3.3.2
  • K355: Konqueror 3.5.5
  • Saf: Safari, 1.2.4
  • IE: Internet Explorer
  • Eli: elinks 0.10.2
  • kaze: kazehakase 0.5.4 w/gecko

Minimo (embedded mozilla) can be used too! To my surprise, everything seems to work, including compiling from webserver. Blocks, written to cookies, are volatile, because minimo - at least my version - doesn't store cookies persistently. Speed is not excellent, on an ARM based iPAQ PDA, and the screen is a bit small for the default 80x25 size window.

jsforth screen shot:
Kwiki Logo