I'm wondering, how does the mathetical community view non-standard calculus/analysis as developed by Robinson? The idea of infitesimals revived seems like a break-through in my eyes. But the fact that is has not yet been adopted by any major institution leads me to skepticism. From those of you have done it, are there logical flaws in the theory? I am really interested in learning it but I fear it may limit me a lot because every mathematical field uses the standard theories.