GNU datamash
This is great work, and runs fast. The documentation is well done and has plenty of examples.<p>Here's an example of datamash and R with timing.<p><pre><code>    time datamash sstdev 1 < data.txt
    288891.28552648
    0.76s user 0.01s system 99% cpu 0.775 total

    time R --vanilla --slave -e \
    "x <- read.table('data.txt', header=F); sd(x\$V1);"
    288891.3
    2.68s user 0.06s system 99% cpu 2.761 total
</code></pre>
(The data.txt file is 1 million lines, each line a random number 1 to 1 million. The timing is on a MacBook Pro Retina 13" 2014)