halfway done
"A is for APL" grabbed my attention and wouldn't let go... I'm posting this in hopes of exorcising it.

A is for APL, with ciphers arrayed.
B is for BASIC, for kids and for trade.
C was successful, from Dennis, of course.
D is dead Dylan, entombed in closed source.
E is the language that limits your trust.
F is for FORTRAN and decks under dust.
G is for Goedel whose failure was tragic.
H is for Haskell's expression of magic.
I is for Intercal made up in fun.
J is for Java left under the sun.
K is like APL sans its strange faces.
&lambda's for Lisp and its fond round embraces.
M is ML so your proofs are all sound.

Update: so much for exorcism... I changed three lines above to steal from the #haskell version.

N is the order of growth we must bound.
O for Oberon's slim binary tersity.
P is for Perl's postmodern perversity.
Q was QBASIC in Microsoft's youth.
R stands for art we were taught by Don Knuth.
S is for Smalltalk and corporate spending.
T is for types and huge flamewars unending.
U is for UML's silly CASE tools.
V is for Verilog -- hardware by rules.
W's web-code, the big killer app.
XML's X, better known as ``that crap''.
Y is recursion so self-referential?
Z specifies everything that's essential.

Dear hacker, once finished with these ABCs,
Go out and make new ones, to play and to please.

shae showed some earlier lines to #haskell and they came up with this which I've edited a bit to scan better, etc. -- both versions need work:

G is for Goedel, a language of logic;
H is for Haskell's expression of magic.

I is for Intercal made up in fun
J in which arrays are so easily done

K is for postdocs in database theory
L is for Lambdabot stuck in the scenery

M is for MLISP which nobody uses
N is complexity which always confuses

O is Oberon, whatever that's Wirth
P is for Pascal and limitless mirth

Q was QBASIC when Microsoft started;
R, RPG when the government farted.

S is for Smalltalk eponymously known
T is for TeX getting blood from a stone

U is for Unix, that's lacking in balls
V is for VHDL in echoing halls

W: Windows which couldn't do shit.
X: XML, differing not a bit.

Y is a combinator everyone knows
Z is for ZetaLisp that nobody chose.