I would like to be able to install Xodo on my work PC. A barrier is that it is not clear if I am permitted to use Xodo free on my work PC.

Please explicitly state whether or not this is allowed and make this very easy to find so that IT departments are comfortable with Xodo.

https://www.xodo.com/contact-sales.html "Corporations and organizations that want to Use XODO for business or commercial use" could be interpreted as an individual within a company can use it free for commercial purposes. However I am sure that my IT department will NOT accept that because it is not clear.

http://feedback.xodo.com/knowledgebase/articles/911262-how-does-xodo-make-money states "The Xodo app is free for personal use and it will stay so." Again no definition of personal and whether personal use while at work and on a work PC is acceptable.

https://www.xodo.com/legal/XODO_Terms.pdf "license for personal, non-commercial purposes" is pretty clear that I CANNOT use it at work. Is that really the intent?

I think there will be a lot of potential users within companies that would like an alternative to Adobe Reader but it's just too hard to justify buying a license. Without explicity stating that the free license is OK for individuals at work then it's not going to get past IT departments.

There are many annotation types: Circle, FreeText, Line, etc. Maybe the most popular type is Highlight, at least in the scientific community. Each annotation type possesses some properties, many of which are common to several types and some of which are common to all types. For example, “author”, “content”, “subject” and “creationDate” are common to all annotation types. There are also properties for an entire document, such as “authors”, “creationDate”, “keywords”, “subject” and “title” which can be very useful even if an entire document is not the main object of interest. The “content” of an annotation (usually called a comment) is the text you put in the pop-up window associated with the annotation. When you highlight a portion of text you can add a comment in the pop-up window. Notice that most PDF software talk about Comments instead of Annotations.

The most important property for handling annotations (and files) is the "subject" property. As before with the old index cards, we need to create topics for our annotations so we can easily classify and find them. It is then normal to use the "subject" property to do this. Most PDF Editors allow you to write topics in the "subject" properties. But, as implemented in most software, if I write many topics in the “subject” property (let's say separated by semicolons), usually those software are unable to Sort, Summarize and Search a particular topic. For example, I enter the following topics in the “subject” property of a given annotation, an Highlight annotation in my case:

scientific method; explanation; scientific truth; testability; Karl Popper

With XChange Editor, if I sort my subjects, the sorting will be applied to the first word in the “subject” property, in this case ‘scientific’, in fact the whole string is considered a single word and if I summarize the annotations by subject, the same problem occurs, the whole string is considered a single word, not to mention that both features can only be applied to one file at a time.

Searching is a bit more powerful, at least in XChange Editor, since the Search Pane has many options to do advanced search. Contrary to the Sort and Summarize features, the whole string is NOT considered a single word. So, in the example above, I can search for “testability” only.

Besides the classic full text search, I like to be able to search within “subject” and “content” property of ALL annotations in ALL PDF files in a folder and subfolders. But since the PDF files are not indexed the search can take a very long time if you have 5 gigabytes of PDF files (which is my case), especially if the search is a full text search.

Also, the results are displayed in the already overcrowded Search Pane. The really good point is when you click on a given result the corresponding PDF file opens quickly to the right place. For example, if I do a search solely within “subject” and “content” property of all annotations in all my PDF files (not a full text search), each line in the result window in the Search Pane points to an annotation in a specific document. If I click a line, the corresponding PDF file opens where the text is highlighted. It’s good but not enough.

So, I think Searching is more powerful than Sorting and Summarizing in most PDF software. Which is why I’m using it much more than Sorting and Summarizing. However, the Search Pane in XChange Editor is all the same not a full fledge annotations management system. For example, I’m not able to have a list of all the subjects I created in the “subject” property of all my annotations!! From the example above, I’d like to have access to something like that in an alphabetical order:

explanation

Karl Popper

scientific method

scientific truth

testability

Right now, I have to keep track manually of all the subjects I created, which is an impossible task. I recall that I talk about 5 gigabytes of PDF files or hundreds of PDF files and thousands of annotations (mostly Highlight).

Now, let’s forget the Sort, Summarize and Search features as implemented by most professional PDF software. Try to think otherwise. Think about a new paradigm to manage annotations.

As I said before, the focus is on annotation not a whole PDF file and we need a way to access all annotations in all PDF files in a device based on subjects created by the users.

So, we need two main windows: a classical window or Document Window to display a PDF file (or many PDF files) and a Annotation Window to display annotations (think about index cards) based on selected subjects. As with the Document Window, it has to be possible to open many tabs in order to work on many subjects or projects on the same time.

The subjects can be listed in a Subject Pane. So the software has to maintain a subject database. From there we can select many subjects at the same time and the corresponding annotations (from all PDF files in a device) will be displayed in an Annotation Window. Of course, the Subject Pane should provide subjects management tools as renaming a subject across all annotations or across a subset of annotations or a subset of PDF files. Many more ideas come easily to mind.

When reading and annotating a PDF file, the GUI has to offer an easy way to enter or create subjects. Right now, with XChange Editor we have to open the Property Pane to get access to the “subject” property of an annotation. It has to be possible to enter or create a subject (or many subjects) directly in the pop-up window just as we fill the “content” property (usually called a comment) in the pop-up window. In addition, the field used to enter or to create a subject has to display a drop-down list of all the subjects already created so that it is possible to select topics that already exist.

It is not necessary, I think, to integrate a kind of project manager. A user has only to create special subjects for his projects. For example, the user can begin all his project names by “Project” followed by a name or a number. For example, he can enter “Project-001” or “Project-Popper and its enemies” in the “subject” property of an annotations.

Also, it is not necessary, I think, to force the user to put all is PDF files in a special folder manage by the PDF Annotator. People already manage PDF files in different ways. Most users already work with a reference manager or a sync service. Anyway, since the focus is on annotations, a PDF Annotator has only to scan a device for PDF files and annotations within those files. It does not matter if the file changes name or location, the software needs only to constantly scan the device for PDF annotations and update his subject database (and his index database for full text search).

If a user uses multiple devices, there is no need, I think, to create another synchronization service, which proliferates like plague on the Web. No matter how a user synchronizes his PDF files (Google Drive, OneDrive, Drop Box, Resilio, etc.), each copy of a PDF Annotator installed on a device works independently from each other and scans only the device on which it is installed.

Yes, I know, there is a software called PDF Annotator (www.pdfannotator.com). In the best case, it seems to be a PDF Presentator and in the worst case it is a toy not a tool.

Now let's talk about Qiqqa.

Qiqqa is the closest thing I saw which can be called a full fledge PDF Annotator. But there are major flaws. Take note that Qiqqa talk about tags, which is the same as the “subject” property of a PDF file.

The biggest flaw is that the main features are not PFD compliant. Annotations and tags (“subject” property) do not comply with ISO standards for PDF format. So, if Qiqqa goes bankrupt you are in big troubles. And even if Qiqqa does not go bankrupt, it's impossible to work on a device that does not have Qiqqa installed, which means you can not collaborate with colleagues who do not use Qiqqa.

Qiqqa has the right idea to focus on annotations and to use tags (“subject” property) to manage annotations (and PDF files), which is quite powerful, but the main window displays PDF files, based on selected tags (“subject” property). To see annotations based on selected tags, you have to generate a report, which is awkward. But Qiqqa is still quite powerful since you can click on an annotation in the report to open the PDF file in the right place. But, it is highly preferable, as I explained above, to have windows (or tabs) which dynamically display annotations based on selected subjects (tags in Qiqqa jargon).

Another big mistake, Qiqqa try to be a big software which can manage all the workflow of a research project. For example, it integrates a reference management system, tools to discover new papers to read and where to focus your efforts, the Expedition tool which automatically breaks your library into themes so that you can quickly get up to speed with and understand your field of research. This may be good ideas, I am not sure, but what is certain is that these functions should not interfere with the main functionality which is the management of annotations.

A great improvement would be if highlights (annotations) that are created could be exported in the same order as they appear on the page.

Many times some highlight is added in the text at a second or third reading that appear before an already existing highlight. But the highlights (as annotations) seem to be exported in the order they are created - per page. So the exported order is not really consistent in the new pdf that gets created.

I don't know if there is any good reason not to export annotations other than the order they appear on the page. But if there is you could always keep that as an option in Settings.