There seems to be no font for the Macintosh that can display properly Hebrew with cantillation marks, a situation I find annoying since my MacBook Pro with OS X 10.5 can't even display in a useful way some Wiki pages I consulted recently. I thus took the time to build such a font, using python and the python fontforge module, starting from the glyphs of Yoram Gnat's Keter YG font.
I first looked for a good corpus of glyph combinations to produce as ligatures, i.e. a repertoire of consonants with their accompanying vowels and marks. The Mechon Mamre site allows downloading such a Bible http://www.mechon-mamre.org/c/ct/c0.htm in a click and I took those html files as my corpus, giving me a little more than 6250 combinations that I wanted to precompose using python with the fontforge python module.
Also, I am no font designer, at all. I thus had to start from an existing font that allows modifications, and since the Mechon Mamre files are based on the Aleppo Codex, of which there is a very nice edition I could get from my university library, the Jerusalem Crown, with a font made by Zvi Narkiss, I chose a font with the same inspiration, namely Yoram Gnat's Keter YG font (available from Taamey Culmus).
Wanting to keep the job as simple as possible, I found no other way than to discard completely the "Hebrew logic" (the Hancock-Hudson layout) used in Yoram Gnat's font, that looked much too complicated for me to handle. I then moved a few dots out of the way to avoid as much as possible clashes with other diacritics; I used a scheme with only 6 marks, namely 'bottom center', 'bottom right', 'top left', 'top center', 'top right' and 'high above'. The idea was simply to reconstruct with a fontforge script each of the combinations occurring in the Crown using the marks and attachments somewhat as they are normally used dynamically in an opentype font; knowing of no tools to do that, I wrote the code for it, but did just the minimum necessary. Another python script generates the mif file and it is ftxenhancer that produced the final font.
Here it is, Keter YG for Macintosh (zip file, 164K and here is how http://www.mechon-mamre.org/c/ct/c2679.htm renders with FireFox on my Powerbook.
Since the Mechon Mamre site encodes 'holamhaser for vav' as 'zwj holam', the font also accepts that combination though it is made to use U+05BA; the font is nothing but ccmp tables and precomposed combinations.
If there is any "big mistake" please tell me fast.