I've written several technical articles for magazines. While I do all of the writing at home, I certainly develop test cases and demonstrations at work.
My recent subjects are:
- - systemd-nspawn
- - openssl enc/rsautl/dgst
- - RFC-1867
- - SMB1/2/3
- - Oracle TNS wrapped with SSL/TLS
...and I have a few things in the queue.
All of these topics are useful at work, and all either grew out of or into work-centric projects.
My employer also provides $0/yr education budget, so this is my way of keeping myself up to date in a manner that I consider reasonable and fair.
I've had no objections so far on this activity.