Who knows what horrors lie in the dark heart of unicode

H̛͎͚̳͇̼͇͔̘̭̳̰̻̰͙̜̩̟̅ͧ̇ͬͦ͊͌ͩ͑ͥ̎̒̈̽͆ͭ̐̚̕ͅĒ̱͓̞̭̙͔̝̼̝̗̞̰̗̫̭̗̟̳̇̄̅ͧ̍ͭ̂̉͌͊ͦ͘͘͟ ̧͎̭̗̮͊̏ͥ͊ͥ̄̉̔ͨ͌̓͗͊̓̂͟C̸̡͇̯̞̤̖̮̳̥͔̽̏̐̍ͦ̌̇ͭ̋͒̔̽͂͋̏͂̀̆̂͜͢͡Oͯͯ̿̆͛͑̾̊̋̌́̒̇̈͊ͫ̂̚͏͏̻̣̻̮̹̠̥͙͍̬͉̖̮̜M̌ͥͥͥͪ͑͋ͪ͐ͯ͛̎̑ͥ͂̑ͯ̏̀͟͡͝҉̥̹̖̗͕̫̠̥̟͇ͅḚ̠͇̺̳͓̦̘̟ͣͣ͌̈́̋̅̾̐ͮ͗̔̾̚̚̕ͅS͂̆̃͗͂̽̔ͯͫ̊҉̴̪̺͈̭̻͎̤̖̗͍ͅ

Zalgo makes an appearance once every few weeks around here, it seems.

Here's a bunch of sources on it:

KYM: http://knowyourmeme.com/memes/zalgo

Zalgo text generator: http://www.marlborotech.com/Zalgo.html

And of course, should you use regex to parse html?

http://stackoverflow.com/questions/1732348/regex-match-open-...

This guy has turned this into an artform https://www.facebook.com/glitchr

W̶̡̡̢͙̗̯̞̯̝̗͕̗̞͇̟͖̘͉͎͚͇̫͈̘̻̺̗̜̺͙͎̣̲͔̗̱̜̗̦͓̬͆̊̓͑͌͋̐͌̍̈̇͊̎̿͂̄̔̋̊͌͐͋͌̂̈́̈́̀̔̈́͘͜͜͠͝͠h̴̨̛̙̞͚͇͇̬̖̹͎̜̯͚̰̫̥̭̬̮͕̼̤̼̗͙̓̅̆̉͑̾̽̋̆̋̆̾̑̎̊̓̔̀̍̀͑̋̌̋̈́̃͘̕͘͝͝͠ͅͅơ̶̡̧̧̨̛͉͚͇͚̪̜̱̟͖̗͔̫͙͙̻̠̣͓̙̺̮͎̼̻̪̪̝̙̌̈́̐͋̾̈͑͋̑́̑̈́̽̔͒̈́̂̄̀̊̂̉̊͒̐͆̀̀͐̏͂͒͗̆͒̋͂̓̏̚͘̚͠͝͝͝ą̷̛̼̪̜̳̳̱͓̗̖̲̣͚̜̝͖͚̟̬̱̹͎̪̰͖̦̹̝̖̑̄͗̐͊̂̈́͋̾͊̄̾̌̌͊̓̂̅̊͊̒̂̄̕̚͝͝ ̶̧̧̧̛̛̛̫̝͖̩̤̫̳̳̟̟͙̟̳̣̦̥̣̳͇̼̪̯̯̪̦͙̞͈̲̺͙̯̻̪̯̮̳̓̿̀̿̈́̆́̋̑̀̂͛̈́͂͌́̾̿̊̒̆͊̍̎͛̔̅̄́̃̍̾̒̈͘̕͘̕̚͜͝͝͝ͅͅͅb̸̧̨̡̢̻̱̳͔͇̙̙̦͔̜̼͕͕͓̼̘͕̳̘̯͔̻͉͇̖͕̝̦͙̪̤̣̂͊̿̎͒̀́̅̓̍̇̐͊̔̿̀̒̈́̇̌̄́̎͘̕͠͝ͅơ̵̢̧̧̡̧̡̢̡̝̗͓̞̪̥̦̰͉͓̯̟̯̲̫̭̪̲̝͈̘̤̫͍͚̭̮̥̬͕͈̰̯̰͔̮̥̹̟̓̈̈́͆̉̔̍̾͒̄̅̑̃̇̈͆͛̈̍̿̓̑͐̒̿̅̂́̈́̄̎̈́̆͆̈́͋̇̉́̌͊̀̕͘͘͜͜͠ͅy̴̧̨̧̨̜͉̪̪̮̹̩͉̮̲̖̞̲̙̼̬̫̱͕̖̯̪̤͑̐̈́͛̏̈͑͐̈́̌̑̑̀̓̆́̈̿̆͛͗͆̅̌̀̎̀̾͂͑́͊̋̽͌̊̓̈́͘̚̚̕͝͝ͅͅͅ,̵̧̧̢̡̨̢͕̗͉̰͉̘̳͎̼̤͙̯͓͚̮̱̠̜͙̗̱͍̩̠͖̘̞͔̗̪͍̱̱̳̘̪͕̪̥͎̤̦̼̻̉̊̍͋̉̎͂̉̃̑͗̀̎͑̿͗͐̔̏̑͌̒͗̉̈́͛̅̓̾̓͋̉̈́̓̓́͊͐͘̕͘̕̚͠ ̴̨̢͔̗̠̲̖̥͓̹̻̬̝̟̼͚̝̪̺̘͖̹͎̟̱͕̙̱̤͉̺͐̈́̓́̊͑̈́́̎̓̀̅̅̋͐͂͑̒̏̔͒͒̒̾́̽̋͗̌͘̕͜͝͝͝͠͠͝ͅh̶̡̨̨̛̛̛̰̙̟̗̠͙̦̫̳̰̗͈̫̰͖̱̞̣̳̘͚̦͓͕̰͍̱͙̱̱͗̀͆̏̉̉̂̇̆̉͋̒̆̿̌̍̈́̆̌̂͂̈́̀͛͂͂̽̀͂̍͂̌̾͆͊̉͑̑͒̚͘͜͝é̵̢̢̧̡̡̫̖̯͙̭͔̫̬̝͕͇͚̹̺̖̫̣̼̙̗̼̟̲̺͖͕͇̪̱̖̩̳̋̀͐͑̓̆̄̓̍̐̐̋̒̏̈́͂̍́̓̿̐̄̾͌̄̓͋̒͒͘͘͠ͅͅr̴̨̧̨̡̢̛̼̝͎͓͍̙̲̲͍̥̻̼͙͎͎̘̼͙̜̗̰̯̤̠̦̬̜̭̳̳͔̤̯͉͖̥̗͈̟̉͋̎͆̊̊̃̆͂̑̇͊̓͂͑̅̌͐̈́̐̊͑́̑̅͐͌͊̿̓̿͆̽̚̚͝ͅë̷̡͖̙̘̠̩̣̞̞̮̟̦̲̟̮̺͈̜̠̘̪̳̲͖̣̗́̄̽̍͒̃̐́̾̓͋͗̅̈́͑̌̔̀͐̎̔́̀̈̿̅̓̉͐̿̃̾̿͒̆̃̅͆́̈́̂̇̕͜͠͠͝͝ ̵̧̡̮͍̹͓͕͇͈̣͈̹͙͔̞̖̳͕͉͎̼̖̹̤̗̠̭͍̜͍̥̯̾̅̈́̌̋̆͛͆͛̋̽͐̅͑͐̇̇̃͂̅̅͗̂̽́̇̄͊͐̐͆͘̚͘̚̕̕͘͝ͅͅw̴̧̧̢̡̡̧̛̛͙̫͍͔̟̜̦͚̘̟͍͉̱̘̘̱̺̻̜͖͉̞̬͚̝͓̫͚͖͈̘̤͉͛̂̓͛̈́͊̾͗̈́̒͌͋͌̐̉̓͛̈́̽͌̾̀̎́͗̆̿͊͘̕̚̚̕̚͜͜͜͝͝ͅe̸̡̧̨̨̡̛̬̪̯̬̣̬̰͎̞̺̘̘̪̯̥̰̫͉͎̯̫̳͚̜̼̭̫̲̰̫͓͉̜͎̳̼̻̗̦̐̌̓̋̑͛̌̓̄̊̏͆͌͛͒̌̐̄̓́̐̎̀̈́͗̔̏̆͑͌̀̑̐̒̑̏͘̚͘͜͜͝ͅ ̶̨̡̧̡̧̨͔̹̤͖͎̹̜̩͍̺̦̰͓̰̫͎̲̼̟̰̩͈̹̮̏̋̄̐̓̈́̍̌̔̊̊̒̒̊͑̓̈́́̓̓̎̈́͒̈͒͘͜͠͝͝͝ġ̷̡̡̪̞̞̟͕̗̦̞̞̩͔̺̫̝͔̹͓̙̯̫͓̺͈͎͉̳͉̝̺̘͙͍̗̤̠̰̗́͂̀͆̔́̎̆̏͆͗̿͂̑̀̇̌͗̆̅̅͌̀̂̀̀̈́̅̈̔̕͝͝͠͝ͅơ̷̢̹͓̝͕̞͕͉̮̦̠͔̮̳͉̲̝̫͖͍͚͍̻̣̹̥̜̹̦͍̰̯͚͓̼̬͔̥͔̝̞͓͙͓͉̊͌͂͆̈́̾̇̆̃̓̋̅̑̃͆͑̃̂͗̀͆͆̽̈́͒̊͘͜͜ͅͅ

And that's only in the left-to-right parts.

Reposting it here as a test :)

w͢͢͝h͡o͢͡ ̸͢k̵͟n̴͘ǫw̸̛s͘ ̀́w͘͢ḩ̵a҉̡͢t ̧̕h́o̵r͏̵rors̡ ̶͡͠lį̶e͟͟ ̶͝in͢ ͏t̕h̷̡͟e ͟͟d̛a͜r̕͡k̢̨ ͡h̴e͏a̷̢̡rt́͏ ̴̷͠ò̵̶f̸ u̧͘ní̛͜c͢͏o̷͏d̸͢e̡͝