Clouds for doing quantum computing are becoming increasingly popular. Here is a list with links of those quantum clouds that already exist or are imminent. All are commercial but usually free for small jobs and open to the public. Most use open source q c software but some don't and have opted to keep their software proprietary. In Alphabetical Order. ✅ indicates working qc hardware.
footnote: I have definite opinions about the strengths and weaknesses of each of these quantum clouds which I will gladly share with you, but only by private channels because this topic is very controversial. I've worked on quantum computing for almost 2 decades, so my opinions on this subject are very well informed. Full disclosure: I used to work for Artiste-qb.net, the authors of Bayesforge, but I no longer do.