In scientific and high performance computing, people are regularly inventing new file formats. Many of these decisions also follow paradigms such as "We don't like XML nor complexity, so let's do as if it was 1980 and serialise these data as ASCII one datum per line".
Don't forget that your viewpoint comes from your community. If you are a CAD person, you probably never use JSON. If you do data research, you probably never use XML. If you do hardware development, you probably open any file with a hex editor anyway just because data is usually some bitstream for you.
Use line-delimited json (jsonl) if you need to store lots of records in a single file -- gzip that file if size is important. foo.json.gz is a common data interchange format supported in data warehousing systems and the like.
First was understanding the approach others had taken as they adapted the flexible open file structure to their commercial softare, so I could read supposedly "standard" files "exported" from established vendors' proprietary formats into my system as data input for post-processing my way.
Then moving all the way upstream to buffer and parse incoming live data using highest priority without losing ANY.
The parsed data is pre-processed as it is prepared for storage and it is written to an open file in raw form according to the peviously determined structure, and a facsimile sent to an autoscaling scrolling graphing module for real-time (+latency) display on the screen.
The commercial softwares that do this use proprietary raw formats, are expensive and confusingly vendor- and generation- specific (even if still supported by the vendor) and did not start out PC-compatible in early versions, plus I needed to interface to some instruments made before there was software anyway.
That way I could collect analog data from antique reference instruments plus process it without limitation compared to various vendors' exposure of fewer-than-needed options. Then export raw files, or those processed my way, in an early mainframe academic extensible file format still openable by today's proprietary softwares, since it was the only format ever agreed upon for interchange by the competing vendors. Plus the old file format had almost completely standardized extensions for the lab application in the 1990's before one of the vendors achieved domination, at which point development stopped in 1998, but there were only a few vendors and they each went with where they were at the time. The remaining standard document and its initial implemenation turned out to function much better with abandoned development, especially since it's so difficult to comprehand, utilize, and implement, that basically each vendor has always known the standard is dead, and these are the _modules that no one must touch_ so there turns out to be far better consistency over more decades than if revisions would have been made along the way.
This was so the rest of the world could enjoy a few of my analog things digitally after that.
The only reason this works is because of the good fortune resulting from all that early anti-lockin standardization effort before there was one dominant player, and from customers who had been expecting it for so long that they were willing to accept a not-fully-completed standard.
Turns out years of delays toward the end were because support from the strongest vendor who had been one of the staunchest advocates of an open standard as they were arising, became a changing landscape as the dominance was building. Instead of engineers, more MBA-type decision makers, who were considering the competitive implications of a more level playing field for customers, were involved in grinding it to a halt.
But it did put me closer within reach for the first time to the machine learning I was doing back in 1980 when I could put together an adversarial system using high level language on a pair of application-specific operating systems using more than one leading vendor's proprietary application-specific language & data structure in a more favorable way than you could on a PC after that type of office machine first gained popularity. Back then it was good having the first desktop (benchtop) multi-user multi-tasking system as well as the largely-competitive-performing single-threaded offerings from other leading research equipment vendors. Not always literally _micro_ processor either, some were bigger than that.
After all, I thought that was supposed to be the advantage of high-resolution digital data, what you could learn & teach from it through computer processing, because archival storage was not the main objective yet since it was too expensive to store the full raw data.
I already knew what slide rules, vacuum tubes, and chart recorders could do.
Anyway, the live (progress) display was just the icing on the cake but it had initiated the whole project because I was finally running out of the big thermal paper that one of my favorite 1970's-design data systems needed for its live high resolution display which it used in place of an analog chart recorder. I had been gifted a large amount of the surplus high-dollar paper refills from the vendor once this generation of instruments was retired, and fortunately it had lasted until I had some slow time and dedicated equipment to do some experimental computer programming. Now that's good customer service, even though I hadn't purchased a new instrument from them for long enough to be considered unsupportable.
The best antique small data systems had a provision for streaming out more live data than they were capable of storing, for those who had access to more powerful generic outboard storage & computing resources like mainframes or eventually SOC's (Some Other Computer) like the early Apple.
After reviewing the revised, photocopied, re-revised documentation needed to interface to the SOC at the time, which was not focused at all[0] on the Apple the salespeople were helpfully encouraging operators to add to their bench, it was understood how actual support was limited to the binder you were looking at.
[0] this would later turn out to be very fortunate
The customer support was excellent and they would try to help out those few small-timers trying to interface to things like the proven hardware from Apple, but their engineers at the time were still having difficulty making it always work trouble-free for these early adopters, and there was no guarantee.
So it should be understood why I always never wanted to do this, and waited decades into the PC age until I was running out of paper and had no choice.
But it had been on my mind for a bit.
I don't often demo it on the laptop but one day I did go to a 21st century digital petroleum exploration conference where they had vendors represented like Halliburton, Schlumberger, and Paradigm. Microsoft had a vendor booth not offering _off-the-shelf_ exploration ware but more like custom projects for the kind of dollars at stake and you know they had people that can do it.
The only demo I did was where an exploration geek showed particularly good understanding and interest in how lab data related to the field. They were at the booth across from Microsoft who watched too but the only thing obvious from that distance was the detailed animated data-collection graph filling my screen as it progressed during that phase. That type display is really not that much different than commercial spectrometer software already. I don't think they were hearing the discussion I was having with the other vendor (maybe with hindsight now I should rethink that). I did have some actual unexpected VC interest from a major at the conference, but that's a completely different story.
Well when the next Windows was coming out, the preview of version 8 had one of the interestingly useful features not found in Windows 7 where when you click for more detailed info during a file transfer, you get a real-time graph instead of just the old progress bar. They plot ups-and-downs of transfer rate against progress with a rate indicator floating along, where labs plot things like ups-and-downs of analog signal across progress.
The odds against all of this happening were phenomenal.
Made me feel kind of like Forest Gump in a way :-)
The rest of the story may or may not be more interesting someday itself . . .