"Link arms - don't make them."

FAQ - Frequently Asked Questions

by Axel Auweter (2 June 2004)
last update: 7 June 2004

What is The SoftPear Project?

The SoftPear Project aims to create IBM PC/Apple Macintosh compatibility software.

Okay, I read that already on the main page. But what does this mean?

Our main goal is to run the Mac OS X operating system on top of a x86 hardware architecture. So IBM PC users may experience the fancyness of Mac OS X without having to buy Apple hardware.

So, another PowerPC emulator? Why don't you use PearPC?

SoftPear is not a traditional emulator. What SoftPear does is called binary translation. Emulators like PearPC simulate a complete hardware architecture including CPU and I/O to make an operation system think it is running on the real hardware it was designed for. With SoftPear, the base operating system including the kernel will be native x86 and only those parts that exist in binary form and are closed source (which is everything that makes Mac OS X nice and fancy) will be translated using dynamic and caching recompilation. By going this way, we hope to gain better performance than it is possible with a traditional emulator. PearPC is a great software nevertheless!

Will I be able to run Mac OS X applications on MS Windows using SoftPear?

No, but you will be able to run them on GNU/Linux.

What is the "base operating system"?

We first thought of using Darwin/x86 as the base since Darwin is the original base of Mac OS X. But our first experiences with Darwin made clear that Darwin/x86 lacks a lot of hardware support. So, another aim of the SoftPear Project is to change the base system to GNU/Linux. We try to stay as OS independent as possible, so maybe it will run on BSD, Solaris and many more systems, one day.

Why do you compare yourself to < insert one of the following projects, here >?

We compare ourself to:

FX!32 because they made code for Win NT/x86 run on Win NT/Alpha. We wanted to run code written for Darwin/PPC on Darwin/x86. See above why we now focus on GNU/Linux as the base system. What also makes FX!32 comparable to SoftPear is it's technique of caching code that has already been translated.
FreeBSD's Linux Binary Compatibility because this is a comparable type of ABI conversion, we are working on. With SoftPear, you will be able to run Darwin binaries on Linux. The difference to FreeBSD's Linux Binary Compatibility is the additional recompiler inside SoftPear.
Wine because wine runs in user space, loads binaries that are not in the host computer's standard binary format (win32) and because Wine did reimplement some of Windows' libraries. SoftPear will run in user space, will load Darwin's Mach-O binaries on other platforms and will provide special versions of Darwin libraries, if necessary.

When will the project be finished?

Well, as you may have read, this project consists of several parts and none of them is achieved within a few weeks. Actually, we don't even know if our approach to Mac OS X on x86 will be successful at all. For us, it is an academic project and if it turns out well, we're happy about it. If not, we at least gained a lot of knowledge about binary translation and abi conversion anyway.

Don't tell me stories, when will I be able to run Mac OS X with SoftPear?

Since great efforts have beend made concerning the recompiler and the loader for Linux, we plan to be able to run at least console based Darwin/PPC applications within summer 2004.

What will be the key-features of SoftPear?

SoftPear will be:

portable, because all development is done in user space. No kernel tweaks necessary.
fast, because only the necessary part (closed source PowerPC code) will be reocmpiled.
faster, everytime you start a program through intelligent caching using fat binaries
free, because SoftPear will be released under the terms of the GNU General Public License.

Hmm, this sounds interesting to me. How can I help?

Help is always welcome. Please note that we're not only in need of developers. Help in the areas of documentation and the website is also appreciated. If you like to contribute, please contact Michael Steil or join the mailing lists.