Internet Explorer and MS Word understand ligatures but a bug is causing them to display spaced out. IE10 displays ligatures correctly when new and degrades after updates. See the problem explained here
My font is a very successful orthographic font. It is the first ever-such font made for the writing system of a complex script (Singhala). Users love it because only three keys differ on the key layout used for it from the US English keyboard and all shifted key positions are intuitive to remember. The first version was finished in 2004.
At that time, it could be used only in Windows Notepad and SIL.org's Worldpad for Windows systems. Apple and Adobe products displayed it with no trouble since its inception. It now has 2500 ligatures. (Yes, thousands). This scared people like Mozilla who allowed it in normal sizes only inside Thunderbird email client. They thought the computer would grind to a halt trying to make thousands of ligatures on a web page. This is one of the myths about ligatures.
By 2008 Applications in Windows, Macintosh and Linux systems showed the font correctly except inside Internet Explorer and MS Word. So, I asked the users to use only Safari, Firefox and Chrome browsers and AbiWord and Gnumeric as alternatives for Word and Excel. (Mozilla later reported that the speed difference between my font and system default font is 2%).
See a web site using it: here. Copy some text in it to a text editor and see the underlying Latin text. This is really romanized Singhala. Think of it like a Fraktur font but many, many times the number of ligatures and shapes gone completely crazy.
When IE9 and MS Office 2007 came out, its ligatures showed but weirdly, each ligature was attached with a trailing gap.
THE DISCOVERY OF THE BUG
This week I casually tried a test page on my daughter's Notebook and its IE10 showed the test page perfectly. I quickly changed programming on that web site to allow IE10 to show the pages in the font (earlier I allowed only romanized text). Then I checked the font inside Word and the results were still the disappointing spaced-out ligatures. When I opened the Font setting dialog, I discovered the bug that has been causing the trouble. The preview shows the correctly formed ligatures but the settings never get taken by the document.
Next day I turned on automatic updates on the Notepad and the ligatures in IE changed to ones with gaps after a massing update. The following day another update reduced the text down to bare letters with no ligatures at all. Surprisingly and happily, Excel 2010 has no problem showing the ligatures!
This page at Microsoft web site is confusing language and script in its description of Standard Ligatures. Could it be that IE and Office developers are also ambiguous about Standard ligatures?
Please read the following page where I describe the case:
Ligature bug in Word and IE