It is difficult to find a good way of keeping a personal journal across different computers; or even to find software that keeps a journal nicely. On Linux I've experimented with Redbook, and for years have also been using a plain text filing system that uses a regimented form of the file name to keep track. However I'm thinking now that a better way may be to use WordPress for this purpose, as, irrespective of whether the journal is shared or private, the writing environment is now pleasant, clean and easy to use, and the journal is always available, whether the blog is shared or otherwise.
I was looking also at Vivaldi's community. They have also started to use WordPress for blogs, which seems sensible rather than diverting valuable time and attention to developing their own blogging platform. I have to admit, I was tempted. But I learned something from my previous experience with Opera (as well as with other platforms). Opera created a really nice networked blogging system that was supposed to be bulletproof, or proof against ever removing it, since it was also the basis of a community around Opera itself. However, eventually they scrapped it. It was very unfortunate. Vivaldi is a nice browser, but, like many small tech companies, it's all dependent upon one man. If were suddenly to sell out to a larger company, be killed in a car accident, or whatever, the future of Vivaldi would be questionable. So it's better to stay with a company like Automattic whose future is more secure.