bitext2tmx is a fast and stable program and a good replacement for the alignment tool in SDL Trados Studio.
The application is not installed, just extract the download file into a directory of your choice and click on the *.jar file to start it.
bitext2tmx is a Java application, so it requires Java in order to work on supported operating systems (Linux, Mac OS X, Solaris, Windows).
Version 1.0 M1 of bitext2tmx is in development.