The metadata use across applications was great and exactly what others tried to mainstream (WinFS et al). You could search quickly for media files, emails, etc. and save the queries for fast access later on. mbox vs maildir, etc.
Edit: And this wasn't slow and of considerable overhead like what we have right now with indexers for OS-wide search.
Just wanted to second this: using BeOS for email, Usenet, etc. where each message was in a single file had an experience which was faster and more capable than email client shipped before Gmail several years in. For things like smart folders, Apple Mail or Outlook on a modern SSD-equipped system has more noticeable UI lag than BFS delivered on a mid-range Pentium.
The really cool part is that it was also portable – there were multiple email which seamlessly interoperated because they were both just querying BFS, which made it faster for developers to experiment with alternative UIs since you didn't have to reinvent or tune a lot of core functionality.
Unfortunately our industry's mainstream systems for the most part have badly done half-hearted implementations of past innovations. What's most disheartening is that for example stuff like low-latency audio isn't reliably available on mainstream platforms. There's always some dance you have to go through if you need it. On one platform the dance takes longer than on others, but the fact remains that even this was no problem on BeOS. I'm not saying BeOS was without faults, but it was a general purpose system and excelled in some regards which hasn't been available in the same quality since, unless you're willing to restrict yourself to certain hardware or API restrictions. The saddest part is that the BeOS IP has since been tucked away inside that Japanese company (Access Ltd?) and is lost to the world. I've tried Haiku but it's not the same. Just imagine if BeOS had been open sourced under an acceptable license back when it actually had good hardware support for its time.
All this is unfortunate yet very obvious result of free market and capitalism. Wherever money goes, technology goes. Android is about to bring back low latency audio. Just like PHP, the whole system is optimized around optimization.
It's up to the people who cares to organize and assemble teams etc etc .. but only rarely it goes somewhere I believe.
I still hope for a sane cpu, sane gpu, sane dsp, all very very open so that a solid software can be written without too much reversing and friction (I saw that tagged pointers architectures were back in research on risc-V so who knows).
I remember feeling physically sad rewatching BeBox (with SMP). The low latency UI while processing 3D and video, all this dynamically... even now it's still not a given on any system. Except maybe macs ?
Agreed - my P90 could seamlessly transfer video from a camera, build Mozilla from source, and surf the web while never missing a frame on music playback. Even now that's not a given, although SSDs have made it at lot less common than it used to be with iTunes.
Speaking of SMP, it's also sad that whenever an x86 or ARM or whatever CPU with more than 4 cores is announced, what's the first thing tech media and most people say? "Who can make use of more than 4 cores anyway?" or "There aren't any programs that can take advantage of more than 2 cores.".
I've never understood how people seem to ignore the fact that you can run more than one CPU intensive application at the same time or even have breathing room for light applications while most cores are busy heavy processing.
I can easily saturate all the cores you throw at me with the usual tasks I'm busy with at a computer, so give me more cores, more memory. And I run highly parallel tasks like image or video processing or compiling code.
On latest Linux kernel from SSD to USB or USB to USB with it's easy to lock up the copying application or even whole machine while data is flushed. It's less of an issue with deadline or bfq i/o schedulers, but it's still there. Now, we copy around at least gigabytes these days, but still. When I was using a Mac, the first thing I always did was to completely disable Spotlight (including all indexing).
Edit: And this wasn't slow and of considerable overhead like what we have right now with indexers for OS-wide search.