I added a column to my Scheme Implementation spreadsheet. That is ‘Arbitrary Metric A’ As the name suggests, it is arbitrary. However, it is also a metric. My opinion about the merits of any particular scheme implementation was not a factor.
Metric A sucks. It cannot be independently verified, it's relevancy cannot be
determined, the bias is unknown. It has exactly one virtue: it has a value.
I'd like to come up with something better, but until I do, here it is.
If you have an objective metric, give me the values, (or better yet, tell us how
to derive them!!!) and I'll add a column for that.
Not only did I have the temerity to measure Scheme implementations on
a hidden scale (it could have been a Ouija board), I had the temerity to rank
the implementations. Furthemore, I divided them into four broad tiers.
Tier 1 is the powerhouse implementations. Of course PLT scheme is the
most popular scheme. I was surprised to find that Gauche is tremendously
popular. I've heard of it, but never used it. I was also surprised,
to see MIT Scheme is still popular enough to stand out from the crowd.
Tier 2 is the usual suspects. These implementations are well known and
have a solid following. The surprise here is that EdScheme is in this tier
but Chez Scheme is not and that Scsh is here but Scheme 48 is not.
Tier 3 is the genus omne.
Tier 4 is the obscure implementations.