Toki Pona is a constructed language with about 120 words, 14 letters/sounds and some 10 grammatical rules.
It came online in mid-2001 and was created by "jan Sonja". The word "jan" means "person", and "jan Sonja" means "the Sonja person".
It can be learned over a weekend and there are some people claiming they've learned it even faster.
It has no consonant clusters, no double consonants, no diphthongs nor triphthongs, no double vowels, no cases nor declination, no tenses, no conjugations, no derivations, etc.
It is said to be based on Taoism and a test case of the Sapir-Whorf hypothesis.
Its Wikipedia has been closed and moved to Wikia and its request for a SIL code has been turned down for the moment, in both cases the absence of bigger numerals are pointed out as one of the main reasons.
On the other hand, an official book ("pu") has been published by "jan Sonja". There are different course available on the internet (most of them based on the translation of the English Toki Pona course by "jan Pije") and on different social media there are some conversation groups or postings about Toki Pona and even in Toki Pona.
Its vocabulary is created a posteriori based on phonetical simplification of words from Finnish, Croatian, English, French, Tok Pisin, Chinese (both Mandarin and Cantonese), Dutch, Esperanto, Georgian, Tongan, Welsh, Swahili and Japanese I hope I haven't forgotten any language.
My interest in the language came in three phases:
At first, the closeness to semantic primes has been my drive for learning it... semantical decomposition is indeed very interesting from a linguistical point of view.
Later, the fact that the 118 classical root word list was very interesting for describing the world from an almost robotic analytical point of view, e.g. "lukin" = see, look and read ; "sitelen" = draw, paint, write ...
And more recently, the idea of using Toki Pona as a worldlang, capable of creating basic conversation worldwide after only a week of time. It can't express everything, but it can get you food and shelter. Party talk and small talk is definitively no problem in Toki Pona.
Stories, myths, proverbs, poems have already been translated into Toki Pona as well as some religious texts and even the novel The Little Prince.
There are also some Comics in Toki Pona online.