BMS vs bmson

Both BMS and bmson have their upsides and downsides.
If you’re unfamiliar with bmson, here is an excerpt from the bmson v1.0 specification:

“bmson is a file format based on JSON.
Compared to BMS, it is a much easier format to handle on both artist and developer ends,
as the format expects games to slice the sound stems during play rather than artists having to do all this work beforehand.
This also removes the limit of keysounds you can have in a single chart,
as well as it lets chart creators to use any part of any sound they want.”

bmson was initially developed by wosderge, hoping it would be used by many.
Thus to help in his agenda, we allow the submission of bmson files in this event.
Unlike BMS, bmson has no keysound limit. This means you can have as many playable sounds as you wish.
The way keysounds are chopped up are up to the chart creator as opposed to the artist.
Instead of having to export every single keysound individually, you can instead export full length stems. No length limit.
This makes the whole process of creating keysounds (playable sounds) much easier.
However, bmson has a major drawback.
Due to bmson being fairly new, it’s largest downside is it’s lack of support.
As of writing this, only 3 games support bmson, those being:

It is worth noting that CircularRhythm does not support beat or popn modes.
Instead, this game uses a circular play field. You can read a temporary documentation about how to create notecharts for CircularRhythm.

bmson also only has two editors:

GLAssist, a tool that assisted in organising charts in LR2, also now partially supports bmson.

All of these softwares are in development, and lack many features you would find in programs such as Lunatic Rave 2 or iBMSC.
With lack of developer support, comes lack of player support.
Due to bmson being the less popular than BMS, you need to expect less traffic to your submission.