As the chart below shows, the number of programming languages beginning with a certain letter varies as much as 10x by letter.

Vis1

Below is the same list, sorted by popularity.

Vis2

A curious observation: why are A and C both ~3x more popular than B?

Data used for these charts:

firstLetter,n
a,59
b,22
c,75
d,20
e,28
f,38
g,30
h,15
i,23
j,27
k,15
l,45
m,57
n,31
o,30
p,69
q,10
r,33
s,76
t,24
u,13
v,13
w,9
x,10
y,4
z,6