The ROOT I/O workshop was held on June 20th at CERN. A few things of interest in MIDAS land:

- LZ4 is now used as default compression (replacing gzip-1)
- JSON class streamer is finally implemented (XML streamer updated/reworked)
- recursive read-write lock class implemented
- do not see any special mention of Javascript I/O or jsroot, but jsroot git repo seems to be quite active

Of these the recursive read-write lock is most interesting - using something similar would improve ODB performance
and presumably fix the existing lock fairness problems.

https://root.cern.ch/doc/master/TReentrantRWLock_8hxx_source.html
https://indico.cern.ch/event/715802/contributions/2942560/attachments/1670191/2680682/ROOT_IO_June_Workshop_v2.pdf
https://github.com/root-project/jsroot

K.O.