These file types are associated with apps for various mobile devices (e.g. Blackberry Java apps). Since these are generally undocumented proprietary compiled formats, they will probably be of little use to you unless you want to reverse-engineer the app. If you do, patience, trial and error, and a hex editor will be needed.
In general, for unknown package formats it's useful to try opening in 7-zip. It's possible that the archive contains files in some e-book format you can read.
From here, we see that an
alx file is an XML document containing a description of the app, e.g.
<name>Sample Network Application</name>
Retrieves a sample page over HTTP connection.
<vendor>Research In Motion</vendor>
<!-- more metadata truncated -->
You can therefore open it in any text editor, e.g. MS Notepad or Notepad++.
cod file is apparently a proprietary encoding of a compiled Java class file. This guy has reverse-engineered the format's header. With some effort you could probably extract the Java bytecode, and then disassemble it using
javap. But unless you're interested in reverse-engineering the app, this file probably won't be of any use to you.
I believe this is a Palm Pilot code format. See whether you can find Palm-related computer software that can read it. If it's just an app, it will probably be of little use to you for the same reason as for
However, it's also been extended into an e-book format, so you could try opening it in an e-book reader like Calibre if you suspect that's what it contains.
As Journeyman Geek pointed out, SIS is an installer package for Nokia/Symbian devices. It might be a renamed ZIP file (try opening it in 7-zip). Since Symbian is partly open-source, you might be able to find better docs for this format.