I thought that understanding program flow was a huge implediment to non-programmers and that if we had graphical flowchart method then at least small tasks could be performed by non-programmers. However, after using ETL software which works exactly this way, I'm much less confident.
Does anyone remember IBM Data Explorer, which became OpenDX?
The program was based on the notion of mapping flows as topological bundles, thus it could (and would) attempt to automatically parallelize whatever independent operations it could. Programs could be set up as, quite literally, flowcharts, with a given box having input hooks (multiple), output hooks (usually single), and a piece of code, usually a C++ library, that would produce or consume the data flowing through the 'pipes'.
I demonstrated this to a bunch of high school kids at a national science fair (ran it on an SGI in Ithaca while presenting at the fair in DC... it was hard to compete with the UIUC Cave VR developers otherwise) and the kids seemed to understand it instantly. Hey, look at that, functional programming in a visual style. What's not to like.
Needless to say it has not set the scientific programming world on fire and the project, while still maintained and used (I believe) by a handful of groups, isn't terribly high profile. A screenshot can be seen on OpenDX.org : http://opendx.org/images/opendx-screenshot.jpg
I 'contributed' the RPM spec file, played with it for a while, but by the time it had been opensourced, I was no longer working in the type of environment where it was a major advantage. Plus I no longer had a pile of nodes to throw at arbitrary computational task nor much need.
Sometimes I miss that sort of thing. Lots of times, actually. I've been daydreaming about it lately... although these days I like to use iPython for that sort of thing, it would be nice if the self-documenting aspect of the UI and the generated programs could be retained.
Khoros[1], AVS[2] and LinkWinds[3] all do the same sort of thing as OpenDX.
I think these sorts of "boxes and arrows" programming systems suffer from being monolithic environments with idiosyncratic interfaces and little or no support for external software engineering tools. What's worse for them is they generally compete for mindshare with scripting languages or scriptable environments (i.e. things like Mathematica) with larger communities.
I don't think they will ever gain wide acceptance until they allow the same level of reuse as systems based on structured text.
