Most well made and reasonably complete fonts should support it, including most of the common fonts. No special application is required, as long as it supports Unicode characters (like Word, Pages, and most other word processing apps these days).

Here's the character: ǽ (In the Unicode table it is hexadecimal 01FD). You should be able to copy and paste it into your word processor. You can also see alternate ways of entering it here: http://www.fileformat.info/info/unicode/char/01fd/index.htm.

Unfortunately, the Unicode specification doesn't include an œ with an acute accent, so that's a different story entirely! :P

I found this interesting link about creating your own, if you like:

http://vlaurie.com/computers2/Articles/privchar.htm

I was tinkering with it, and found it fairly simple to modify an ae with an accent by just dragging others in. I believe you can then save it to a fontset and give it a hexadecimal code.

I sound so much smarter about this than I really am. Or dumber. I really can't tell.

Why use the ligature <æ>in any case? It is not authentically Latin of the classical and patristic period, but was introduced in medieval times, because the pronunciation of had become equivalent to that of , which is what occurse in many manuscripts. I must say that I find it unfortunate that the Vatican Missale Romanum Editito typica tertia (2002) still uses it. Even more so the digraph <œ> for .

Arthur,
I can quite understand that for some there is a genuine attraction in digraphs/ligatures, and these were certainly favoured in the 19th century. I personally feel that they are a distraction from the text - just as Gothic lettering gives a spurious 'religious' flavour to texts and notices. Of course, on 'authenticity', I could be mischievous and say 'Liturgiam Authenticam'!

Tom Dawkes,

Would you agree that "meæ" is easier to read than "meae"?

For me it is not stylistic preference that dictates the use of the ash (æ), but 1) accurately reproducing chant texts from different periods of time, and 2) like JMO I find æ to more easily be automatically sung as a single syllable. Probably if I was fluent in speaking Latin then it wouldn't matter ("queue" is fine since I'm a native English speaker), but since I'm not, it helps a bit in chant execution.

Also, regarding accents on capital letters: I think that to say they look ugly is entirely subjective. Modern Spanish rules require appropriate accents over uppercase letters, unless the letters form an acronym (http://buscon.rae.es/dpdI/SrvltGUIBusDPD?lema=tilde2, #7). I wouldn't be surprised if accents over uppercases were omitted because of difficulties in typesetting and type foundries, but modern typography has come a long way in typography and improving readability of type, which is why some outdated customs in type are left behind. (E.g., for many who learned to type on a typewriter, they were taught to put two spaces after a period because it helps legibility on non-proportional type. But in modern word processing this style is almost universally reviled now since it adds extra space without improving legibility. Unless you're using Courier or Consolas as a body text, but... :) )