JDB is a package of commands for manipulating flat-ASCII databases
from shell scripts. JDB is useful to process medium amounts of data
(with very little data you'd do it by hand, with megabytes you might
want a real database). JDB is very good at doing things like:

    * extracting measurements from experimental output
    * re-examining data to address different hypotheses
    * joining data from different experiments
    * eliminating/detecting outliers
    * computing statistics on data (mean, confidence intervals,
      histograms, correlations)
    * reformatting data for graphing programs

Rather than hand-code scripts to do each special case, JDB provides
higher-level functions.

JDB is built on flat-ASCII databases.  By storing data in simple text
files and processing it with pipelines it is easy to experiment (in
the shell) and look at the output.

WWW: http://www.isi.edu/~johnh/SOFTWARE/JDB/index.html