problem with regular expression
You could do

reshape2::recast(
  data = setNames(strsplit(language, ", ", T), language), 
  formula = L1~value, 
  fun.aggregate = length
)
#                                                                L1 Assembly Go R Ruby Rust Java Javascript SQL C C++ Haskell Matlab PHP Swift Perl Bash Python
# 1                                                          C, C++        0  0 0    0    0    0          0   0 1   1       0      0   0     0    0    0      0
# 2                                                            Java        0  0 0    0    0    1          0   0 0   0       0      0   0     0    0    0      0
# 3                                                         Java, C        0  0 0    0    0    1          0   0 1   0       0      0   0     0    0    0      0
# 4                                     Java, Javascript, Ruby, SQL        0  0 0    1    0    1          1   1 0   0       0      0   0     0    0    0      0
# 5                                                      Java, Ruby        0  0 0    1    0    1          0   0 0   0       0      0   0     0    0    0      0
# 6                                          Javascript, Ruby, Bash        0  0 0    1    0    0          1   0 0   0       0      0   0     0    0    1      0
# 7                                             Perl, Javascript, R        0  0 1    0    0    0          1   0 0   0       0      0   0     0    1    0      0
# 8  PHP, Javascript, Ruby, Assembly, Swift, R, Matlab, Go, Haskell        1  1 1    1    0    0          1   0 0   0       1      1   1     1    0    0      0
# 9                                         Python, PHP, Javascript        0  0 0    0    0    0          1   0 0   0       0      0   1     0    0    0      1
# 10                                                              R        0  0 1    0    0    0          0   0 0   0       0      0   0     0    0    0      0
# 11                                    Ruby, Assembly, R, Go, Rust        1  1 1    1    1    0          0   0 0   0       0      0   0     0    0    0      0