Libidn FAQ -- Anticipated Frequently Asked Questions. Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Simon Josefsson See the end for copying conditions. Q#1: Why doesn't Libidn use a separate library for the Unicode operations? A#1: Separate libraries (Glib, QT, libiconv) seldom mark the Unicode tables with the corresponding Unicode version they implement, nor do they provide a interface where a specific version can be requested. This violates the stringprep specification which requires that a specific version must be used. Also, some of these third party libraries depend on non-portable behavior (e.g. threads). Q#2: Why do Libidn include several stringprep profiles? They waste space! A#2: The stringprep profiles included are usually derived from the generic stringprep tables, and doesn't waste more than say a few hundred bytes (see profiles.c). The Unicode normalization tables and the generic stringprep tables are roughly equivalent in size, although the latter tables can surely be compressed much further. They occupy about 100 kilobytes on typical platforms. However, if in the future several large Stringprep profiles are added, configure options will be added to help reduce size. Q#3: I thought GNU was encouraging libraries to be licensed under the GPL? A#3: The reasoning for this was for libraries that provide unique functionality to encourage more free programs. Since there are several IDN libraries out there, using the GPL for Libidn would only encourage people not to use Libidn which would not help the spread of free software. Q#4: How do I add a new stringprep profile? A#4: Add the profile definition to profiles.c, export the symbol and optionally add a CPP macro in stringprep.h.in (and document it in stringprep.c). If you want to add self tests, do it through tst_stringprep.c. Mention it in NEWS. ---------------------------------------------------------------------- Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.