QEMU

What do you like best?

best this is its open-source, and quite well maintained. Quite versatile support for different hardware emulation and one can add support for their own hardware quite easily.

As its also used by virtualization solutions, it needs to fulfill different use cases which has helped in the overall evolution of the QEMU's design.

One more good thing is the community is quite active. In case if you find a bug and send a patch for it, they will give it a nice review and will actively work on it so that it gets submitted in time.

What do you dislike?

Not much to be honest. Documentation for getting started with QEMU can be sometimes a bit hard to move around. Its not because there is some problem with it, its mainly because of the rich feature set and tons of options. Finding the ones that you care about can be tricky sometimes.

Recommendations to others considering the product:

I would suggest to create a simple guide yourself of the options you need and their descriptions along with some example commands to run it.

It comes handy while doing context switches. Specially when you are not in touch with the work for more than 2-3 weeks.

What problems are you solving with the product? What benefits have you realized?

Once I used it to port our ARM hypervisor on RISC-V architecture. Even though the hypervisor extension for RISC-V is not released yet, but because its in the final stages, someone added QEMU support for it. So basically now we have a RISC-V hypervisor ready before even any chip is launched with that support. In short it allowed us to get ahead by almost 1.5-2 years in the market.

I also one used it to port an RTOS on RISC-V architecture. Boards are quite expensive when they are released initially.