spell-check install

content/install.txt

@@ -38,7 +38,7 @@ Debian (and derivatives)
 The easiest way to install Kwant on a Debian system is using the pre-built
 packages we provide.  Our packages are known to work with Debian "wheezy" and
 Debian "jessie", but they may also work on many other recent Debian-derived
-sytems as well.  (For example, the following works with recent Ubuntu versions.)
+systems as well.  (For example, the following works with recent Ubuntu versions.)
 
 The lines prefixed with ``sudo`` have to be run as root.
 
@@ -116,7 +116,7 @@ Mac OSX: MacPorts
 =================
 
 MacPorts is a full-fledged package manager that recreates a whole Linux-like
-environment on your Mac. Beside Kwant, MacPorts gives you access to a wealth of free softwares which you can install on your computer
+environment on your Mac. Beside Kwant, MacPorts gives you access to a wealth of free software which you can install on your computer
 easily (using simple command line instructions). It requires few choices to be made by the user,
 and provides the simplest way to install Kwant.