Modafinil (sold under the brand names Alertec, Alertex, Altasomil, Aspendos, Forcilin, Intensit, Mentix, Modafinil, Modafinilo, Modalert, Modanil, Modasomil, Modvigil, Modiodal, Modiwake, Movigil, Provigil, Resotyl, Stavigile, Vigia, Vigicer, Vigil, Vigimax, Wakelert and Zalux among others) was was originally developed in France by professor Michel Jouvet and Lafon Laboratories (1970s).
In many countries it is currently a prescription-only medication, and is used to treat sleepiness due to narcolepsy, shift work sleep disorder, or obstructive sleep apnea. There are ongoing clinical trials for its use in fatigue, cocaine addiction, attention deficit disorder, depression, seasonal affective disorder, bipolar depression, nicotine addiction, and schizophrenia.
It's also widely used by the military to keep operatives awake for long periods - and unofficially by shift workers and students studying for exams etc etc.
Its mechanism(s) of action have been very widely researched, but as yet there is no official consensus on how it works. To the extent that it's been called 'a drug in search of a mechanism'.
See: Mechanisms of modafinil: A review of current research Neuropsychiatric Disease and Treatment. 2007 Jun; 3(3): 349–364.