Consider this context: under Windows, start can generally be trusted to attempt some useful "launch the application/document/item/...", very much as command-line open does under Mac OS X.
At a policy level, one also often hears, "Well, there are good standards for installing an application under Windows (or Mac OS X), but Unix (or Linux) is 'all over the map'. Unix needs a framework so we don't have to develop a separater installer/... for each flavor."
The Portland project [L1 ] aims to fulfill that need.
LV Sigh - yet another project where someone decides they don't like any of the existing solutions, so they go off to create their own silver bullet. It may be wonderful. Who knows? What I do know is that it is a non-trivial task to set out to create a framework that would be used on all unix and unix-like systems. Sun did it with NFS . And perhaps, someday, someone will do it with installation. But the way to do it is to clearly identify what is broken (not just what doesn't work the way you want it too, or what is done in dozens of different and incompatible manners.). And if Portland has done this, it should be one of the first things one sees when they visit that web site. I don't see that today.
At least, it does, very broadly. While several bright people [provide references] are enthusiastic about Portland, CL regards its ambitions as severely limited. Even when the first couple of releases of Portland are complete, it will leave many, MANY questions of interoperability unanswered. 2007 might end with Portland only creeping past its x86-Linux GNOME-KDE base.
On another hand, Portland has good people working on it, it seems to be meeting its modest deadlines, and it does help with several specific technical issues. For example, xdg-open [L2 ] is close to the start mentioned previously.
[Mention that, while the command-line interfaces are likely to continue to be of most interest to the Tcl crowd, C bindings will eventually appear.]
[Provide magazine references.]
"Portland provides desktop portability" [L3 ]