I found that sentence in this text. In this context:
It would be difficult to find two languages that are the communicating coin of two more different cultures than those gathered around these two languages.
The writer is saying, that the two (programming) languages, lisp and pascal, are constructed very differently and have very different idioms and data models which result in a different type of community around these languages as the languages are used for different purposes and are developed in a different style. Despite the fact that they originate from / have their origins in a now defunct language, Algol60.
He is saying, that despite their shared inspiration, they are very different and it would be difficult to find two other languages that share a similar origin and remain so diametrically opposed. So I would interpret it something like this:
Scheme, a dialect of Lisp, is equally similar to earlier versions of Lisp and a now retired language, Algol60. You can see the elements/patterns of Algol60 in Pascal which is still used today. What is interesting about this, is that despite these languages inheriting many ideas from Algol60, they are used and developed very differently. Whereas Pascal is very solid and unchanging, Lisp has a more organic development
A simpler way of communicating what I think the author was going for would be:
It would be difficult to find two communities more different, than the two for these two languages.
- "These" is plural of "this"
- "Those" is plural of "that"
The "these" is referring to the two languages i.e. this language, these languages. "Those" is referring to the communities that use the two languages. So, that community vs those communities.
"gathered" means "brought together" the author is saying that people have created a community together around these languages.
"communicating coin" is not an idiom I'm familiar with. I suspect, given that there are not any mentions of it via google books, that this is likely to be an idiom directly translated from another language into english. In context, I think the author means something along the lines of "language of choice" but that is a guess.