You might want to download Apples developer tools(XCode)  If you sign up as a free developer you can download it for free from Developer.Apple.Com.  Inside of the folder Developer/Applications/Utilities there is a nice little program called FileMerge which displays things side by side in a nice manner.

-Mark


On Feb 12, 2012, at 8:23 PM, Nobumi Iyanaga wrote:

> Hello Mark,
> 
> Thank you very much for all your help!
> 
> I ended up with the following script:
> 
> -----
> 
> property script_fname : "DocComp.sh" -- your "external script" name -- by Kino, 2006-05-20
> 
> property file_1 : ""
> property runtime : 0
> property firsttime : "yes"
> property firstfile_passed : "no"
> property secondfile_passed : "no"
> property filetypes : {".txt", ".html", ".rtf", ".rtfd", ".doc", ".docx", ".wordml", ".odt", ".webarchive", ".xml"}
> 
> on idle
> 	if runtime < (current date) - 5 * minutes then
> 		set file_1 to ""
> 		quit
> 	end if
> 	return 1
> end idle
> 
> on open (droppedItemsList)
> 	set my_path to POSIX path of (path to me)
> 	set shell_scpt to quoted form of (my_path & "Contents/Resources/" & script_fname)
> 	
> 	set runtime to current date
> 	if (number of droppedItemsList) ≥ 3 then
> 		display dialog "This droplet accepts two files."
> 		return quit
> 	else if (number of droppedItemsList) = 1 then
> 		if firsttime = "yes" then
> 			display dialog "Please drop another file..."
> 			set firsttime to "no"
> 		end if
> 		if file_1 = "" then
> 			set file_1 to first item of (droppedItemsList)
> 			set file_1 to POSIX path of file_1
> 			return
> 		else
> 			set file_2 to first item of (droppedItemsList)
> 			set file_2 to POSIX path of file_2
> 		end if
> 	else if (number of droppedItemsList) = 2 then
> 		set file_1 to first item of (droppedItemsList)
> 		set file_1 to POSIX path of file_1
> 		
> 		set file_2 to second item of (droppedItemsList)
> 		set file_2 to POSIX path of file_2
> 	end if
> 	if file_1 = file_2 then
> 		display dialog "You have chosen the same file. Quitting..."
> 		return quit
> 	end if
> 	
> 	repeat with i in filetypes
> 		if file_1 ends with i then
> 			set firstfile_passed to "yes"
> 		end if
> 		if file_2 ends with i then
> 			set secondfile_passed to "yes"
> 		end if
> 	end repeat
> 	
> 	set thename_1 to do shell script "basename " & quoted form of file_1
> 	set thename_2 to do shell script "basename " & quoted form of file_2
> 	
> 	if firstfile_passed = "no" then
> 		display dialog "The first file \"" & thename_1 & "\" is not of the supported types. Quitting..."
> 		return quit
> 	end if
> 	
> 	if secondfile_passed = "no" then
> 		display dialog "The second file \"" & thename_2 & "\" is not of the supported types. Quitting..."
> 		return quit
> 	end if
> 	
> 	display dialog "Comparing " & return & thename_1 & return & "with " & return & thename_2
> 	
> 	try
> 		do shell script "/bin/sh " & shell_scpt & space & quoted form of file_1 & space & quoted form of file_2
> 		--set res to the result
> 	on error errMsg
> 		display dialog "An error occurred: " & errMsg
> 	end try
> 	
> 	set file_1 to ""
> 	set file_2 to ""
> 	set firsttime to "yes"
> 	set firstfile_passed to "no"
> 	set secondfile_passed to "no"
> 	quit
> end open
> 
> -------
> 
> The "DocComp.sh" compares two files (of different types) with Unix diff, and displays the result in a nice (readable) rtf file with TextEdit. I will upload the result in my web site, when my friend, Kino, will give me the permission.
> 
> Thank you very much again!
> 
> Best regard,
> 
> Nobumi Iyanaga
> Tokyo,
> Japan