So, yah, a while back I was wondering why Law and Chaos didn't have their own languages, and thinking that they should. This is what I came up with:
Anarchal: Aka, grunt. Anarchal has no written form. It is not a language which lends itself to being recorded things that are said, and if a native speaker wants to say something to someone who's not present, he'll probably go find him. Some of the more stuck-up (lawful) commentators believe the language is exceedingly primitive and is not capable of transmitting complex ideas. In fact, there is even debate on whether it is a language at all, as their is a startling lack of conformity between speakers. That being said, more powerful beings are able to express very complicated ideas indeed, and the lack of conformity is to be expected. The more skilled the speaker, the closer Anarchal is to an audible rendition of their mental state.
Mechanics: As noted, anarchal has no written form. Understanding a speaker requires a Sense Motive check at a DC equal to 10+1/2 their hit dice+Int bonus. A person who does not know Anarchal may still make this check and understand the speaker, but may not reply in kind. Close knowledge of the speaker (friend, family, intimate friends/lovers) grants a bonus on the check.
Axiomin: The language of Law, Axiomin has no spoken form. It is the language of contracts and records, native speakers believe that anything truly important should be written down and remembered. Axiomin is an exceedingly complex language and poses a significant problem for learners. Even the Lawful exemplar seem to have difficulty with this language at times, so a tridrone will use a simpler vocabulary than a Hepton.
Mechanics: Unlike other languages, Axiomin is treated as a skill in which a character must take ranks. The better a writers command over the language, the more their written contracts and such represent their true desires, so the letter of a contract or agreement becomes closer and closer to the spirit of that agreement. Axiomin contracts are universally watched over by a Kolyarut Inevitable. The HD of the Inevitable is determined by the check result used to write the contract and the HD of the author. In general, the Inevitable is advanced enough that it is a threat to a being of equal power to the author.
Angelic: More on this tomorrow.
Celestial: Is the 'Good races each have their own language' thing spelled out as cannon? It seems a good place to reflect some of the critical differences between the alignments. Good Outsiders all sharing the same language, because they place such a high value on being able to talk out differences, Evil Outsiders having a plethora of languages, that kind of thing.
I like Anarchal and Axiomin to some extent, but I think that Axiomin should be a Decipher Script check, not it's own skill. Let's face it Decipher Script is used so seldom that it isn't a huge change.
Also, I think that Anarchal should have no grammar, syntax, or vocabulary, and instead just be a string of syllables that can theoretically express any concept in the multiverse, but in practice, generally wind up not meaning much. Kind of like "Chaos-speak" but without the punctuation, spaces, and vocabulary.
Axiomin, on the other hand, should basically just be the most perfect language in the multiverse. By which I mean, there should be one term, and only one term, for every concept in the multiverse that the Modrons have ever encountered. Also, it should be a logorithmic language (like Chinese) where symbols represent concepts, not sounds. Every concept, not matter how complex, should have its own character. For instance, the concept of "Falling out of a tree due to ones own incompetance, which results in injury" would have its own symbol.