Just to butt in with some HTML, you can add pre-formatted text tags to get charts to line up correctly. You just need a <pre> at the beginning, a </pre> at the end, and use the space bar (not 'Tab') to even things out. Here's Pied Piper's chart as an example:

<pre>

  Frequency       Interval ratio       Name
                  expressed as within
                  1 octave (2/1)
  
  A   440Hz       1/1                  Tonic
  x2  880Hz       2/1                  Octave 1
  x3  1320Hz      3/2                  Perfect 5th
  x4  1760Hz      1/1                  Octave 2
  x5  2200Hz      5/4                  Perfect Major 3rd (2nd Octave)
  x6  2640Hz      3/2                  Perfect 5th (2nd Octave)
  x7  3080Hz      7/4                  Harmonic 7th (2nd Octave)
  x8  3520Hz      1/1                  Octave 3
  x9  3960Hz      9/8                  Major 2nd
  x10 4400Hz      5/4                  Perfect Major 3rd (3rd Octave)
  x11 4840Hz      11/8                 Augmented 4th/Diminished 5th ?
  

</pre>

As to equal vs just tunings, I suspect I use just when I sing - especially harmonies. I've tried recording myself over myself. If I memorise the harmony and sing it separate from the melody, I'm out of tune. Probably because I'm using equal-tempered scales. If I can hear the melody while I sing, I can adjust my voice to sound right.

See Bruce Olson's website for a version of ABC "Trial version of ABC player and tune stressed note-keynote-mode and mode number coder. Play just intonation or 12 tone equal temperament scale for tunes in ABC notation in large files of ABCs. Requires MODETABL.TXT and .DLL files below. New 08/14/02- Plot up to 8 tunes simultaneously, with adjustable scale factors and origin, and see what the % of total time is used for each note."