Most of the books are in Polish, because this is the language I know the best and I write in it most often, however I will exaggerate saying and writing that it has revealed all its secrets to me.
Many books are in English, because I know this language well – at least it seems so to me, anyway, native speakers usually do understand what I write, although sometimes they are linguistically confused.
Almost as many books are in Esperanto – this is a beautiful idea which has been collapsing beautifully like so many other beautiful ideas... do I know Esperanto well? I don’t know, because probably nobody knows what this would mean.
There are a few books in French, though there should be none, because I know French rather poorly: fortunately these texts are short, so readers won’t be tormented long. 

There are quatrolingual, trilingual and bilingual editions, however more often the different language versions are separate volumes. Of course there are unilingual editions, too. Some of them will remain one language because they should be so, some maybe will get other language versions, but this is not very sure for I’m simply getting short of time. 

The different language versions are not identical. This is so because they can’t (languages are not identical) and because they needn’t. Translating my own texts I’m in a very comfortable situation I can never be in when I translate texts by other authors – I am in the head, in the mind of the author, thus translating myself is more like writing a new version of a text than really translating it...  

Assuming that a written language is something different than a spoken one, should different fonts be considered different languages, or at least dialects, slang, patois? For all my books I select fonts carefully, for many I design them specially...