Also, just because something is "your own work" in the sense that you created it doesn't necessarily make you the copyright holder at all.
I'll add to this that, contrary to patents and copyright, which are government-granted artificial monopolies intended to favor invention and creation (debating if the employed means efficiently promote the claimed ends is off-topic here), trademark rights core basis is accurate information to customers about what they buy/use, and where it comes from. This is why Mozilla denied Debian the right to use the brands "FireFox" and "ThunderBird" for the custom builds that went by default with the distro, because they had no say on the modifications (I vaguely heard an agreement was being worked on, but I've had no news of it for a while).
Arduino is open-source hardware, its design covered under CC BY-SA 2.5. Which is actually a funny situation: the BY clause of Creative Commons imposes attribution. If the Schmuck Company sold Arduino-designed boards under the name Schmuckware, without referring to Arduino, it would infringe on the CC license. But now companies fight for the right to use Arduino as a brand. For the exclusive right to do so, in fact. Looks like something has been overlooked when Arduino has been made open-source: CC doesn't cover trademark issues.
Honestly, I think Smart Projects has the best legal grounds for claiming the trademark but, legal matters aside, this situation is quite ridiculous. To stay in spirit with the fact that it was made open-source, and avoid those legal turmoils, an association enforcing the standard, and the trademark, should have been established from the very start. Something similar to the SD-Association for SD cards, maybe.
Ditto. I use ThunderBird (well, IceDove these days), and I kinda love it, but I'm well aware that e-mail clients have been relegated to oddities. And I do have my complaints about ThunderBird, by the way. I'm tempted to browse the whole of its source in order to track down the line of code that makes it open any message at random when you open a directory, then file a patch to eliminate it.
E-mail clients could be so much more than they ever were, though. And without breaking any protocol. But e-mail itself has lost a lot (not all) of its relevance because of spam, despite there existing protocols specifically aimed at killing the latter. Inconvenient for base users, yeah, but that's where clients could have provided facilitating tools. That's why fenced environments gained traction, again.