No, it is a closed source IBM product. I've seen copies of its installation media on "warez"/"abandonware" sites before, but there is no emulator for it so you can't run it unless you have real hardware. IBM has recently got quite keen on porting open source software to its Unix compatibility environment (PASE) – it is a way for IBM to make it feel fresher and more modern and more accessible to mainstream developers, for only a modest investment of resources.

Even if you download the installation media from one of those sites, you can't run it because there is no emulator for it. Now, it is POWER, so in principle there could be an emulator, but QEMU only supports running Linux and AIX, not IBM i. Probably if someone wanted to, they could enhance QEMU to support running IBM i, but it would be a lot of work – IBM i exploits various obscure features, not just of the CPU, but also of the firmware, which AIX doesn't, and so understandably QEMU/etc don't implement those obscure features. Commercial emulators don't really exist either, because if you start selling a commercial emulator, it is almost guaranteed IBM will sue you.

I think an emulator for the classic CISC hardware would be really cool – probably make the most sense to start by emulating System/38, then try to extend it to CISC AS/400. Who would ever carry out such a gargantuan and pointless task? Probably some day, eventually, someone will do it. And it will be cool.

There were commercial third party emulators, of sorts, for the System/38, such as California Software Products' Baby/38 package. However, Baby/38 wasn't full system emulation, it was actually just an RPG compiler which supported the System/38 dialect, and had a limited emulation of OS services which RPG programs commonly used. They later followed up with a successor, Baby/400. I'm sure it was quite useful to people back in its heyday of the 1990s, trying to port their RPG business applications to Windows. Practical, but not very interesting from a technology perspective.