1. https://support.mozilla.org/en-US/kb/change-program-used-open-email-links
2. "listed HTML file" - ?? If you are talking about the default bookmarks.html file that is sitting in your Profile folder - that file doesn't have your bookmarks, it only has the default bookmarks that come with Firefox.

I don't want to run the mail program, I want to run another program. Maxthon allows me to do this using External Tools. Does Firefox allow me to run other programs without leaving Firefox?

2. Firefox allows me to load an html file which contains my bookmarks, but it doesn't load the bookmarks file. is there a solution?

I stumbled upon this old question

Firefox allows me to load an html file which contains my bookmarks, 
but it doesn't load the bookmarks file. is there a solution?

I am not too sure what you are doing.Use bookmark folders to organize your bookmark Are you storing what you refer to as bookmarks in your own personal HTML file ?

You should import them into Firefox, and use Firefox's built in bookmarks library. See

• Import Bookmarks from an HTML file
• Bookmarks in Firefox
• Use bookmark folders to organize your bookmarks

What program did you want to run?

There are add-ons that can do this Go to the Mozilla Add-ons Web Page {web link} (There’s a lot of good stuff here) and search for what you want.

Hopefully you got your HTML bookmarks file imported by now. In past threads, there were some problems with certain versions of Safari which inserted a couple extra tags in the file that choked Firefox's importer. If you are running into that, see: https://support.mozilla.org/questions/1051547#answer-702421

Regarding toolbar buttons for launching external programs, this extension has an active community of folks to who help one another figure out how to build those: https://addons.mozilla.org/firefox/addon/custom-buttons/

Try:

• External Application Buttons 2: https://addons.mozilla.org/firefox/addon/external-application-button/

You can also do this with PrefBar:

• PrefBar: https://addons.mozilla.org/firefox/addon/prefbar/