Gathering @fossfreedom 's and @Rinzwind 's ideas about 7z and Archive Manager, and tweaking with some of my own, I guess ive found a nice solution:

Archive Manager (actually File Roller) supports 7z (as long as p7zip package is installed), and 7z supports WIM (thanks guys!). But here is the catch: File Roller does not know that 7z supports WIM. So the trick consists in "fooling" File Roller to think WIM files are actually 7z. Sure, renaming (or appending) WIM filenames with ".7z" extension works. But it can be more elegant than that.

Ive downloaded and and examined File Roller's source code, and found out that it (thankfully) detects files by mime types, not filenames.

So the complete solution could be:

• Make sure you have p7zip package installed. You can install it with the following command:

  sudo apt-get install p7zip-full
  

• For Mime-Type dababase editing, install assoGiate (File Types Editor). Its a very easy, intuitve, well-polished tool. A must-have for mime-type editing. Saved me more than once, including now

• To install it in Ubuntu 12.04 (Precise), use the following command:

  sudo apt-get install assogiate
  

• To install it in Ubuntu 14.04 (Trusty), you need to install libgnome-vfsmm-2.6-1c2a manually at Launchpad. In "Published versions", click on the release of your architecture. In the next page, download the *.deb file in "Downloadable files". We need to install libxml++2.6-2 available in Universe repo too, so we can install assoGiate using dpkg:

  sudo dpkg -i libgnome-vfsmm-2.6-1c2a_2.26.0-1build1_amd64.deb
  sudo apt-get update
  sudo apt-get install libxml++2.6-2
  sudo dpkg -i assogiate_0.2.1-3_amd64.deb
  

• Open it in Menu > System Tools > File Type Editor

• At it, go to Type > Find (CTRL+F, or search icon), type "7z".

• Select x-7z-compressed, go to Type > Edit

• Go to Filenames tab, click on Add button

• Type *.wim, click Add

• Close all dialogs, and presto!

• Nautilus now show the WIM archives as a 7-zip archive. Which, given that is 7-zip that handles them, it is not entirely false. No renaming needed, filenames are intact.

• Double-click them, and good ol' Archive Manager opens them with no complains. No need of wine or any weird GUI

Note: these changes in the mime-type database are valid for the current user only. For a system-wide change, open File Type Editor as root:

gksudo assogiate &

Last but not least, for command line, all these steps can be skipped, and the following can be used:

7z x INPUTFILE.wim -oOUTPUTFOLDER

The man pages are usually get installed with software. So, If you install a software with manpages, the manpages will be automatically installed.

Manual pages in a Web browser

• By installing man2html

  You can install man2html package to your computer to view the manual pages in your favorite browser:

  sudo apt-get install man2html
  

• By installing doc-central

  There is another tool which view manpages in browser, it is called doccentral. You can install it with the following command:

  sudo apt-get install doc-central
  

Downloading manual pages:

You can download the latest manual pages from here. The size was also included in the page

Manual pages in PDF !:

Yes, you can even get the manual pages in pdf file format. for example, if you want to generate manual page for man the command will be :

man -t man | ps2pdf - man.pdf.

This will generate a manual page, named man.pdf in the current directory of the terminal. replace man with your desired one, such as grep or apt-get etc.

Info pages in browser.

Though it is not asked in the question, I include it as general reference.

You can also have the GNU info pages (which are more elaborate and helpful) in a web browser by installing info2www package. The command is below:

sudo apt-get install info2www

Hope this will help