Adobe’s CFF engine is an advanced rasterizer for the Compact Font Format whereas the FreeType open source software is used for font rendering on over a billion devices that use either Linux, Android, Chrome OS, iOS and other Unix flavour.
As explained in a blog post, in OpenType fonts, which are an extension of TrueType fonts, outlines for glyphs can be described in two ways – original TrueType outline format and the CFF format. CFF fonts are capable of very high quality display, but the technology places the burden for the display quality on the text rasterizer.
With displays getting smaller, there are quite a few things that need to be balanced to display text properly – “making the text readable, ensuring that no characters are too light or too heavy, consistent height and width, all while respecting the original typeface design.”
This is where CFF rasterizer from Adobe plays its part as the CFF engine in FreeType produces quality text display that is “more faithful to the typeface design.”