I would like to take another stab at the idea of hybrid PDFs as a saveable document format as a way to increase adoption of the ODF file format. I've read bug 79811, but the tone of the discussion left a bad taste in my mouth, so I'd rather start with a clean slate.

A hybrid PDF is a delightfully subversive format. It enhances PDFs in such a way that they become better editable. But they are still PDFs, which are universally supported for viewing. Libreoffice has some basic support for editing normal PDFs. This is nice for people who want to change some text in a PDF without using proprietary tools. Now, saving a document as a PDF in Writer with the hybrid option turned on gives the PDF additional structure so you can use Libreoffice's more powerful editing features. If you don't know what kind of PDF you're dealing with, opening a PDF either gives you simple editing capabilities, or the full power. Either way, it's better just viewing the file.

You can see how a hybrid PDF format could be used to flood the market with ODF documents and LibreOffice: any LibreOffice user who wants to create a PDF can just save the document as a PDF, which would by default be fully editable by LibreOffice. This has a number of advantages over plain ODF or plain PDF:

* everybody and their dog can read your document
* the PDF has much better structure if you want to edit it
* LibreOffice has best-in-class editing support for PDFs

That last point is important: LibreOffice will become known for being the best option for editing PDFs, certainly in the open source world and maybe even considering the proprietary alternatives, precisely because you can leverage all existing editing features of LibreOffice.

Then the delightfully subversive part comes into play: everybody who starts using LibreOffice to create PDFs that are better editable also wittingly or unwittingly starts spreading the ODF format. Soon, there will be market pressure for other PDF authoring programs to add ODF editing capabilities. Here I think it would become useful to join the PDF standardization effort, because "editable PDF's through ODF payload" can become an actual standard. This standardization process could for example alleviate the duplication of data that is inherent with the current hybrid PDF format.

Scope:

I think hybrid PDFs only make sense for Writer, Impress and Draw, as those kinds of documents are often consumed in a read-only way. It doesn't really make sense to create PDfs of spreadsheets or databases because their use lies in modification.

When everything fails:

The aforementioned scenario is a utopic course of events. Let's say that hybrid PDFs are not that successful and they don't actually replace standard PDFs at all. In this case, what remains is that users of LibreOffice have an easy and powerful way to create editable PDFs as part of their daily workflow and they can use them to do normal work. That's a win.

Downsides:

The other bug report uncovered some technical difficulties such as it being quite some work to move the functionality from Export to Save, it being slow to open, and increased filesize of each document. I don't think any of these are unsolvable, but it does make it less attractive as the default format for sure.

Another concern that was raised was that users might expect other software to also be able to save these editable PDFs when they actually can't, thereby losing the user's work. Of course causing data loss is a big no-no, but I don't think it is LibreOffice's responsibility when other productivity suites fail to meet the expectations of their users. The solution is clear: other software suites should also support PDFs with ODF payload.