Bill Seymour Asserts His Right to Bear Arms

Blazon
Per pale, 1st Argent, a decrescent Azure; 2nd Azure, a decrescent accompanied at the horns with two crosses humetty in fess Or; a chief Sable, semé of billets and quadrates Argent, representing a stylised image of a computer keyboard.
Crest: on a Wreath Argent and Azure, issuant out of flames proper, a phœnix Sable feathered Argent.
Registrations
United States Heraldic Registry, #20080913B, 13 September 2008
American College of Heraldry, #3185, 22 September 2008 (“feathered Argent” absent from the crest)
Additional requests for the full achievement
(image above emblazoned by Lorrie LeJeune)
The phœnix in the style of an O’Reilly animal.
Motto above:  Ave, Mundus
Motto below:  Computo Ergo Sum
The symbolism (if you really care)
C and C++ are computer programming languages. Unfortunately, it’s Really Bad Form to put text on a shield since it can’t be read easily in the heat of battle. Luckily, the crescent moon is a recognized heraldic device; and with the horns pointing to sinister, it suggests the letter C. Also, a cross is an honourable ordinary; and drawn humetty, it looks just like a plus sign.
Azure charging Argent is intended to suggest the blue-on-white “C” on the cover of the first edition of Kernighan & Ritchie’s The C Programming Language. It’s hoped that Or charging Azure suggests the yellow-green on mostly blue cover of the third edition of Stroustrup’s The C++ Programming Language, although that might be a bit of a stretch.
I’m a wires-and-pliers guy by training and early vocation; but about thirty years ago, I discovered that I was pretty good at coding; so I began a new life as a programmer. That’s the phœnix; but you probably already guessed that. It’s explicitly blazoned “Sable feathered Argent” to make it possible for the emblazon to pay homage to the O’Reilly animal books, some of which have also been a source of information for me.
The motto above the crest is an allusion to the first sample program in K&R which writes “hello, world” on the user’s terminal. This has become iconic for one’s first program.
The primary motto is taken from Descartesfamous line. Luckily, “computo” is a real Latin verb that has approximately the meaning that a native English speaker would expect. I actually prefer “codeo ergo sum” after the recent English verb, to code (to write part or all of a computer program); but it has been suggested that, because it might seem that I’m trying to make a verb out of “codex”, someone looking only at the Latin might think that I’m becomming a blockhead.
Not part of the symbolism (about which you probably care even less)
From the point of view of a C ideologue, C++ is sinister and beyond the pale.