Lojban Book: This lojban book is covered by a Creative Commons license. The author chose an attribution only license. The language definition is public domain. “In accordance with the Logical Language Group, Inc. policy, certain Lojban language definition materials are placed irrevocably in the Public Domain”
Loglan: A brief mention that you need a license to create loglan materials at the bottom of this page. A book on Loglan with a “single use” type license. The infamous Loglan v Lojban lawsuit was fought on the basis of Trademark infringement. The trademark claim was not upheld because loglan was considered a pre-existing term for logical languages. The suit didn’t decide any other issues.
Laadan: Mrs Elgin seems to be using an informal non-commercial creative commons license. She says, “If some media mogul were to try to publish a Láadan grammar or use the language in a movie or anything of that kind without involving me I would fight that, on principle. But otherwise, Láadan is on its own.”
Given how rarely a constructed language has commercial value in and of itself, lax description of terms is probably okay.
Klingon. The KLI has a rumored license to work with the language from Viacom/Paramount Pictures/Etc. Here is their copyright notice. There has been no known tests of Paramounts legal rights to Klingon the language, but if it was tested, it would probably rely on the word “Klingon.” In any case, the likely battle would be between a Klingon writer v Paramount and Paramount is better funded to defend what ever interpretation of the law they like.
Mandol’a: Copyright Lucasfilm 2007. Here is the author’s take on copyright concerning the language, which in my opinion is directed at the problems of commercial novel writing & fan fiction, and isn’t very well suited to constructed languages. This Terms of Service talks specifically about the starwars.com web site. So far, I’ve only found news articles that say George Lucas is tolerating noncomercial fan films. I haven’t found where this permission is put into text, or if and how it would relate to Star Wars langauges.
Esperanto. Zamenhoff disclaimed intellectual property rights to the language on first publication of his first book. He was very progressive on that account. Esperanto is so well established, the only intellectual right any one stands up for is the copyright to their document, same as if it was written in English or any other natural language. Here is an example copyright on a grammar guide by Don Harlow.
Tolkien Fans. Here is a fan page, (or at least I think it is a fan page). Interestingly he claims a copyright on his derivative work at the bottom of the page.
Teonaht. No license or copyright mention at all (which could also be said of most conlangs posted online). When this happens, I’m pretty sure we are in the world of copyright and legal precedent, which in my not so humble opinion, is rather unforgiving to users of a language. Copyright law, after all, was meant to protect the interests of movie, book and music publishers.
Blissymbolics. The inventor was smart and crazy, and not deviant (in the sociological sense of being different from the norm), but as in mentally ill (probably having mood and affect disorders). He sued the hospital for using and developing his ideographic artificial language and was paid a settlement $160,000 to go away. Personally, I think the hospital felt sorry for him. The dollar amount of the settlement and the legal decision, in my opinion, hardly establish what a language is worth or how the IP issues invovled in conlangs would be resolved