You can use the python library Nikola to generate a static blog web site with the source code also uploaded to the site for FTP download if need or can be stored on github or a similar service in which case all the information to regenerate your site can be downloaded with git or mercurial. All of your posts are actually stored as ReStuctured Text.
You add posts from the command line, regenerate and publish your site
Comments facility can be provided as one of:
- DISQUS
- IntenseDebate
- LiveFyre
- Moot
- Google+
- Facebook
- isso
With the first of these at least allowing you to export all the comments for download.
- Free (Gratis & Open Source) and portable - works on OS-X, Windows 7-10, Linux, Raspberry Pie, etc.
- Download your site source, (if you don't have it already), by a various mechanisms - the source is very small so downloads are fast.
- All your authoring is done offline, from the command line or in just about any editor and published when **you ** choose.
- Content can be written in any of:
- reStructuredText
- Markdown
- iPython Notebooks
- HTML
- PHP
- any of Textile, DocBook, LaTeX, MediaWiki, TWiki, OPML, Emacs Org-Mode, txt2tags, Microsoft Word .docx, EPUB, Haddock markup
- Does not require any server side scripting, or software, so just about any hosting service is suitable.
- Fast uploads - only the changes are uploaded when you publish a new/updated blog entry.