We have lost one of the greats of our community.
I first met John Hunter when he came to give a presentation about matplotlib at the Space Telescope Science Institute in 2004 (or thereabouts). I remember being blown away by how capable matplotlib was (even then), and stunned by John's drive to build it completely outside of what was paying the bills.
Years later, when I started working at STScI in 2007, one of my first tasks was to add some new features to matplotlib. Little did I know, it would become my passion as well. I was a little intimidated to be working on something so entrenched and widely used. But John somehow instilled confidence in me with his support of what I was doing, even as I was ripping apart old assumptions in the code and turning it over anew. Through all the e-mails, conference calls and chance conference meetings with John since, he has been the most encouraging mentor and a prime example of open source stewardship. I should be lucky to find even a fraction of the enthusiasm, skill and leadership that John had.
Equally impressive has been watching so many of us Scientific Python types, separated by geography and institutional affiliations, come together in supporting each other at a time like this. Sometimes it really is more than just code.
If matplotlib has been useful to you in any way, please give generously to the John Hunter Memorial Fund.