It was an issue for Tcl and OO systems:
http://journal.dedasys.com/2010/03/30/where-tcl-and-tk-went-...
> Somewhat related to the large Tcl vs small Tcl issue was one particular extension, or extensions to the language that was noticeably absent: a system for writing “object oriented” code. Tcl, at heart, will never be an OO language through and through, like Ruby or Smalltalk, but that doesn’t mean that an OO system for it is not a useful way of organizing larger Tcl systems. Indeed, Tcl’s syntax is flexible enough that it’s possible to write an OO system in Tcl itself, or, optimizing for speed, utilizing the extensive C API in order to create new commands. Over the years, a number of such systems have arisen, the most well-known being “Incr Tcl” (a play on the incr command, which is akin to += 1 in languages like C). However, none of these extensions was ever included with the standard Tcl distribution or somehow “blessed” as the official OO system for Tcl. This meant that a newcomer to Tcl wishing to organize their code according to OO principles had to pick a system to use from several competing options. And of course, newcomers are the least able to judge a complex feature like that in a language, making it a doubly stressful choice. Furthermore, even experienced Tcl programmers who wanted to share their code could not utilize an OO system if they wanted their code to work with just standard Tcl. Also, if their code had a dependancy on some OO system, it would require the user to download not only the extension in question, but the OO system it was built on, which, naturally, might conflict with whatever OO system the user had already selected! As of Tcl 8.6, thanks to the work of Donal Fellows, Tcl is finally integrating the building blocks of an OO system in the core itself, but this effort is probably something like 10 years too late.