If by 'older posts' you mean early 2000's and prior, the open source Lisps weren't as many or as good as they are today. CCL is open source (back then it was c

If by 'older posts' you mean early 2000's and prior, the open source Lisps weren't as many or as good as they are today. CCL is open source (back then it was closed source under the MCL banner), SBCL didn't exist in it's current form (that was announced in 1999) etc. In general, each decade back you go, think of whatever open source software that even existed as being significantly less powerful, performant and buggier. Many open source projects (esp. the GUI applications) started life as bad imitations of not much better commercial software vs. what you're used to seeing today. And to top it off, you were running it on radically less powerful hardware (in the early 90's you could still watch windows on the screen being redrawn on 'high end' hardware) so any software performance issues you had were magnified by the systems you were running on.