I don't see how cursive script makes Arabic less “modern.” It might make carving it onto stone a bit harder, but the printing press, the typewriter, and the computer all had no problems producing quality Arabic type.
Having written code which renders Arabic text, I found “joining” up the letters to be quite simple. It's just a few rules to choose which glyph to display for each character depending on context. The tricky bits, I found, is in integrating a right-to-left script with systems which were made with only left-to-right in mind.
Ever tried dealing with vertical column text (e.g. Japanese?). I haven't myself, but the fact Microsoft made fonts on Japanese versions of Windows have special "@"-prefixed versions rotated 90 degrees, so if a document is written in it, then changed to that font and rotated, it's the right way up, makes me suspect it's pretty difficult.
That sounds like the result of a lack of forethought when designing the font rendering code, and not because it's a big problem. I've used vertical Japanese text input extensively in Word without any problems.
mixing RTL and LTR is a pain in unix-like tools (gnu, os x).
What I usually (not always) found out diring my experiments woth Persian is that the gnu tools themselves deal with it quite fine - but the terminal application shows them at pretty random places. If there is both LTR and RTL in one file, havoc usually ensues.
(persian also has this funny "invisible space", but it causes only small annoyances)
I digress, but I think this is one of the most annoying things about Unix these days. I practically live by the command line; but terminals are terrible. We're basically emulating technology that was already getting obsolete in the 70s!
Plan 9 had the courage to shed this cruft by having simple text windows which have a prompt. No curser addressing and no crazy control codes. That makes rendering it just as easy (and beautiful) as rendering text box contents. I wish the Linux desktop environments would follow suit.
Having written code which renders Arabic text, I found “joining” up the letters to be quite simple. It's just a few rules to choose which glyph to display for each character depending on context. The tricky bits, I found, is in integrating a right-to-left script with systems which were made with only left-to-right in mind.