I can't see all of them since the site is down, but it looks like they could be from yEd / yFiles: https://www.yworks.com/products/yed https://www.yworks.com/pr

I can't see all of them since the site is down, but it looks like they could be from yEd / yFiles: https://www.yworks.com/products/yed https://www.yworks.com/products/yed