Merge pull request #72 from frootloops/master

Fixed typo

Author: lattner

Diff for: README.md

@@ -2,7 +2,7 @@
 
 **Welcome to Swift!**
 
-Swift is a high-performance systems programming language.  It has a clean
+Swift is a high-performance system programming language.  It has a clean
 and modern syntax, and offers seamless access to existing C and Objective-C code
 and frameworks, and is memory safe (by default).