I *think* the OP is asking "Using the ArduinoISP sketch, I can use an Arduino as a device programmer for burning code into some other (bare) processors, even if it isn't Arduino code. I'd like to have a list of which "other processors" can be programmed that way."
In that case, the answer is that ArduinoISP supports what Atmel/Microchip calls "ISP programming", which is SPI based. At least in theory, you can burn code into any AVR that supports this ISP progamming method. That includes most ATmega and ATtiny chips, up through about the time of the Microchip acquisition. It does NOT support newer chips like the Mega-0 (ATmega4809), Tiny-0, Tiny-1, Tiny-2, or AVR-Dx, all of which use a new programming protocol called UPDI. It also doesn't support "xmega" chips (which use "PDI"), the utra-tiny "braindead" chips like the ATtiny10 (uses "TPI"), or certain older chips that require "High Voltage Parallel Programming" or "HV Serial Programming" (ATtiny28 and ATtiny11 come to mind. Not that you're likely to be able to buy either of those.) It also doesn't support the HV programming modes of the mainstream chips, which is annoying if you want to re-use the RESET pin as IO because you need "just one more pin."
But ArduinoISP is not the only "programmer" software for an Arduino. There is other software, sometimes with additional hardware requirements, that will support UPDI and HVPP, for example. I've even heard of software that will allow an Arduino to program the 8-bit PIC chips (in their "low voltage serial" programming modes.)
I'd be shocked if someone hasn't written something that does SWD for ARM chips (although that gets "complicated", and may require a Native-USB-capable Arduino to properly implement "CMSIS-DAP" and work with host-side software like OpenOCD.
But if you're serious about programming a variety of chips, you should probably shell out the $35 for something like a "Microchip SNAP" programmer/debugger. (or wait for it to go on sale, sometimes 50% off.) These support a wide variety of chips and programming protocols (8bit PIC, 16bit PIC, 32bit PIC, ARM, AVRs of several sorts. And also debugging using the native debug protocols, which is ... sometimes very much more useful than using "print" to debug. (but not always.)
Which chips are supported by the Arduino IDE and "Cores" is a separate question.