You have many choices since you're already using XeLaTeX. :) There's a nice compilation of List of CJK fonts on Wikipedia. FOSS fonts are labelled as such in this list.
As for "a single font that covers essentially all of the CJK code points, rare as well as common", choices are more limited there.
[Updated; it's 2020 now!] AFAIK there is no single .TTF or .OTF that does that (I guess the file size would be too big).
You may want to go for Noto Serif CJK SC, Noto Serif CJK TC, Noto Sans CJK SC, Noto Sans CJK TC. (They are also known as Source Hans Serif/Sans, 思源宋体/黑体)
There are also font projects that distribute two separate font files, which together will cover the entire CJK codepoint range. Two open-source fonts that do that, that I'm aware of, are:
Then using a recent version of XeCJK (as outlined in this answer to your earlier question) (example below uses Han Nom):
\documentclass{article}
\usepackage[fallback]{xeCJK}
\setCJKmainfont{HAN NOM A}
\setCJKfallbackfamilyfont{rm}{HAN NOM B}
% NOTE: "rm" for \setCJKmainfont, "sf" for \setCJKsansfont, "tt" for \setCJKmonofont
% and others for \setCJKfamilyfont.
\begin{document}
漢字源𣴑
\end{document}
As @LeoLiu stated, the kanjis in Hanazono look very 'japanified'. Han Nom looks much better for Chinese text hanzi (to my eyes anyway). Nevertheless, you didn't mention if you're working on Chinese text specifically: you just said "CJK". In any case, both Hanazono and Han Nom contain glyphs for hiragana and katakana, but unfortunately not hangul.
Best Answer
Following the documentation of the
calligra
package at http://ctan.org/pkg/calligra, try this minimal example:Note that loading the package enables the
\calligra
command to change the font. The package also provides the\textcalligra{}
command to set runs of text in that font. Either option is more convenient than loading the font yourself.If you want to load the font yourself however, try
\fontfamily{calligra}
, with the font name in lowercase. (Take a look at how the package loads the font for an example; or see Herbert’s answer for details.)If these don't work, then perhaps the font package is not installed. It is available under both MiKTeX and TeX Live; see your distribution’s instructions for installing packages.