It can certainly be done properly, even on relatively static systems like Unix. See Cristiano Giuffrida's Ph.D. thesis on "Safe and Automatic Live Update" [1],

It can certainly be done properly, even on relatively static systems like Unix. See Cristiano Giuffrida's Ph.D. thesis on "Safe and Automatic Live Update" [1], or, if you don't want to skim through 197 pages, the significantly shorter master's thesis "Safe and Automatic Live Update for Unix Applications" [2] by Calin Iorgulescu. The research has been supervised by AST and since incorporated into MINIX 3. [1] http://www.minix3.org/theses/Cristiano_Giuffrida_PhD_thesis.pdf http://www.minix3.org/theses/Cristiano_Giuffrida_PhD_thesis.... [2] http://www.minix3.org/theses/Calin_Iorgulescu_Master_Thesis.pdf http://www.minix3.org/theses/Calin_Iorgulescu_Master_Thesis....