Hi Tim,
    Having recently retired from 27 years in the aerospace business
as a systems engineer and computer engineer, I have worked (and done
research concerning) a number of high-performance, numerically
intensive, mission-critical sensor data processing applications.
    While modularity, reuse, and components, et al have been
attractive selling points for such systems, hard performance
requirements dictate otherwise. CORBA, Java, and COM would
definitely not be my first choice. Squeak in its present form
would most definitely not make the cut. We have used professional
Smalltalk systems and watched them hopelessly fail under load.
    Back in the early days, we used operating systems and any number
of tools for development purposes only. The final application was
built directly into the hardware. While the hardware has improved by
orders of magnitude since then, so have the performance requirements.
    IMNSHO, these issues are why we still don't have a functioning
Dynabook after 32 years. Sure, I can load an episode of Star Trek
into my VCR and watch folks carrying around tablets that communicate
with humans, each other, and the onboard computers built into the
Enterprise. But back here in the 21st Century, all I can do is load
Squeak into a Titanium PowerBook and dream, dream, dream..... :-)
Someday, my dreams will come true (hopefully, before the 23rd Century).
Cheers, Roger.....

Tim Rowledge wrote:
> 
> "Roger Vossler" <rvossler at qwest.net> is widely believed to have written:
> 
> >     While modularity usually gains a certain amount of flexibility, the
> > price paid is a big hit in performance.
> What gives you this idea?
> 
> In the particular case of Squeak plugins, the lookup when an external
> prim is first called might involve finding a file loading it, doing an
> OS binding/search etc, but that only happens once. On susequent uses,
> the cost is rather small - an extra couple of indirections perhaps.
> 
> In the case of Smalltalk code modules of the sort we have been
> discussing recently, I imagine that any sensible mechanism will
> effectively be as fast as any other method lookup.
> 
> What cases of a modularity cost have you seen?
> 
> tim
> --
> Tim Rowledge, tim at sumeru.stanford.edu, http://sumeru.stanford.edu/tim
> Useful Latin Phrases:- Furnulum pani nolo = I don't want a toaster.