/h/, derived from the Spanish /x/. Its origins can be traced to SMS language. It is widely used in a Filipino youth subculture known as Jejemons.
mdr: Esperanto version, from the initials of multe da ridoj, which translates to "lot of laughs" in English.
mdr: French version, from the initials of "mort de rire" which roughly translated means "died of laughter", although many French people also use LOL instead as it is the most widely used on the internet.
mkm: in Afghanistan "mkm" (being an abbreviation of the phrase "ma khanda mikonom"). This is a Dari phrase that means "I am laughing".
ptdr: French variant from pété de rire – literally meaning "broken with laughter"
rs: in Brazil "rs" (being an abbreviation of "risos", the plural of "laugh") is often used in text based communications in situations where in English LOL would be used, repeating it ("rsrsrsrsrs") is often done to express longer laughter or laughing harder. Also popular is "kkk" (which can also be repeated indefinitely), due to the pronunciation of the letter k in Brazilian Portuguese sounding similar to the ca in card, and therefore representing the laugh "cacacacaca" (also similar to the Hebrew version below).
חחח/ההה: Hebrew version of LOL. The letter ח is pronounced [/x/ /x/] and ה is pronounced [/h/ /h/]. Putting them together (usually three or more in a row) makes the word khakhakha or hahaha (since vowels in Hebrew are generally not written), which is in many languages regarded as the sound of laughter.
ㅋㅋㅋ ("kkk" or "kekeke") and ㅎㅎㅎ ("hhh") are usually used to indicate laughter in Korean. 'ㅋ', is a Korean Jamo consonant representing a "k" sound, and 'ㅎ' represents an "h" sound. Both "ㅋㅋㅋ" and "ㅎㅎㅎ" represent laughter which is not very loud. However, if a vowel symbol is written, louder laughter is implied: 하하 "haha" 호호, "hoho."
(笑): in Japanese, the kanji for laugh, is used in the same way as lol. It can be read as kakko warai (literally "parentheses laugh") or just wara. w is also used as an abbreviation, and it is common for multiple w to be chained together. The resulting shape formed from multiple wwwww leads to the usage of 草 ( 草 meaning grass, read as kusa), due to its resemblance to the shape of grass.
Connery, Brian A. (February 25, 1997). "IMHO: Authority and egalitarian rhetoric in the virtual coffeehouse". In Porter, D. (ed.). Internet Culture. New York: Routledge. pp. 161–179. ISBN0-415-91684-4.
Russ Armadillo Coffman (January 17, 1990). "smilies collection". Newsgroup: rec.humor. Retrieved December 22, 2006.—an early Usenet posting of a folk dictionary of abbreviations and emoticons, listing LOL and ROTFL