@Billt

A lot of open-source stuff from Linux uses the untar then ./configure then make method of compiling to install. When porting such things to AmigaOS, does one use an Amiga configure program/script, or does that part go away?

How unpacking archive (by untar or by zip or by bzip) just depens of how archive packed, so all those "tar -zxvf archive.tar.gz" its not 100% necessary, but yep, you can unpack it in the same manner from the shell, or by unarc, not so matter. About "./configure and make" - in some cases software will have it, in some will have other deps (cmake, scons, makeconf and other stuff), or just bunch of source files , and it will be your work to find out how to compile and build all of this.

If it is used, does one have to rewrite the program's configure information for ./configure to use, or should it work with Amiga's ./configure setup as it is?

To make "configure" works for any more or less normal project (not very small one), you will need to play a bit with configure itself, check on the stage of configuring error log, and add correct deps , if aos4 not grabs them automatically by any of reassons.

Does one need to use abc-shell for that?

In most cases plain amiga shell are enough , but when is not, then abc-shell.

P.S. Are answers available for both OS4-native coding/compiling as well as for cross-compiling from Linux on my laptop, as my laptop is what I'll mostly be able to access and use? (I do plan to get my XE running a VNC server soon though)

If you have plans to do porting from unix world, then you better to setup cross-compiler for a numeric reassons: 1. It will be fast 2. There will be no problems with "./configure" at all, and in most cases its all will be automatically, all what you will need its add something like "./configure -host=cygwin -target=ppc-amigaos". 3. Cygwin will have all those "cmake, autoconf and stuff", which not available on aos4 natively (and because of it, some unix projects possible normally to compile only on cross-compiller setup). Through, its all not that easy as someone can think, its too simplicifyed by users , and everyone start to think that ports its only ./configure; make, while is not. Usually you will need to add some work (and sometime quite a lot work) into the code of porting programm itself, to make all of this works as should, like amiga-kind path, adding stack cookie, removing of forks, porting of necessary 3d party libs for making final linking, fixing endianes issues if they present, rewriting some parts of code in case of limitations in some areas and so on.

I've ported a lot of linux stuff using macosx, linux and windows using cywing. You have to set up a correct enviroment to work without any problem. Regard the port itself, well, this depends from the project. You could port a simply library without any problem. Just specify the prefix and the host in the configure command: ./configure --prefix=/usr/local/amiga/ppc-amigaos/SDK/local/newlib --host=ppc-amigaos and this is the trick. But if the project is a large project you will have to change a lot of things. Keep in mind that actually cygwin is the slower enviroment.. maybe you should try to set up a mingw enviroment instead of the cygwin one, but cygwin is more complete and unix scripts will work without any problems