Esperanto: Designed by a Polish speaker who wants to speak Italian

Toki Pona: Designed by an English speaker who wants to speak Japanese

Loglan/Lobjan: Designed by (a science fiction author/a committee of USENET users) who want to speak the logical notation from Russell and Whitehead's "Principia Mathematica"

Ido/Novial: Designed by (French/Danish) speakers who want to speak Esperanto but can't pronounce it

Lingwa de Planeta: Designed by Russian speakers who want to speak Novial but with more non-European cognates

Ithkuil: Designed by World Wide Web users who want to communicate by telepathy

Solresol: Designed by a French speaker who wants to be a bird