When I have started up mp on Debian Linux with the following command

++++++++++++++++ command
/opt/mono-1.1.13.2/bin/xsp --appconfigfile /var/www/mojoportal/mojoportal/Web.config\
--root /var/www/mojoportal/mojoportal --port 80 --https --verbose --nonstop &
++++++++++++++++ /command

and requested the site, the web server responded the request with "Not Found
The requested URL / was not found on this server.". On the console I got the message:

Adding applications from config file '/var/www/mojoportal/mojoportal/Web.config'
Listening on port: 80 (auto-detect SSL3/TLS1)
Listening on address: 0.0.0.0
Root directory: /var/www/mojoportal/mojoportal
No application defined for: :80/
No application defined for: :80/
######################### /bug

######################### patch
So I have added

++++++++++++++++ patch code
<configuration>
    <web-application>
        <name></name>
        <vhost></vhost>
        <vport>80</vport>
        <vpath>/</vpath>
        <path>/var/www/mojoportal/mojoportal</path>
    </web-application>
    <!-- application specific settings -->
++++++++++++++++ /patch code

to the Web.config and afterwards mp started up as intended. As I have already mentioned, I run mp only with the puristic&fast xsp.exe web server.

######################### /patch

Best regards
Alexander Orlov

P.S.: The forum have swallowed up my origin posting but fortunately I have "backuped" it before I have clicked the Post button. ;(

Please don't add that to the Web.config.  The webapp config file used by xsp (typically with a .webapp extension) and the Web.config file are not intended to be the same thing and combining them might not work with future versions of xsp.  From the xsp man page:

WEBAPP FILE FORMAT
       The format of the .webapp files used for --appconfigfile and --appcon-
       figdir is:

       <apps>
       <web-application>
               <name>{appname}</name>
               <vhost>{virtual host for application}</vhost>
               <vport>{port for the application}</vport>
               <vpath>{virtual directory in apache}</vpath>
               <path>{physical path to aspx files}</path>
               <!-- <enabled> is true by default -->
               <enabled>{true|false}</enabled>
       </web-application>
       </apps>

       You can include any number of <web-application> nodes, one per ASP.NET
       application to run.

       There’s a sample.webapp file in the XSP samples directory.

If you don't want to write a webapp config file, you can use (with an unmodified Web.config):

/opt/mono-1.1.13.2/bin/xsp --applications '/:/var/www/mojoportal/mojoportal/'  --root /var/www/mojoportal/mojoportal --verbose --nonstop &

BTW, I removed the --port option you had since 80 is the default.  I also removed the --https option you had because I don't think it will do anything unless you use some of the other options to specify the cert/key to use.

Hope that helps,

--Dean