cwal 1. Is there possibility to upgrade the license within X amount of time? The free is fine for quick testing but if I were to try and use and/or develop with this, its not useable. So I would buy the personal license and if it works well I would start offering this as a solution to my clients for which I would need the Unlimited license. Essentially I would buy the personal license for personal/testing but in theory require the Unlimited license.
You mean upgrade from Personal to Unlimited license after x amount of time? That should be fine.
Just a side note since you mentioned "and/or develop this this". The index.php is open to modify, but the javascript where most of the app-logic lies, is minified and source files will not be provided. It may be limited how much you can customize/develop Files Gallery. Even if you do, you will likely lose the possibility to upgrade. Customization isn't officially supported.
cwal I understand this is not "open source" per se due to the license, but is there ways to extend functionality without editing the code, so that upgrades are still possible? I saw a thread about a (now defunct) plugin for pre-caching images, but could such a setup be used for creating additional features via the _files/plugins structure? Or some other way. I also saw a thread where someone built a user registration system, but this seemed to be integrated directly into index.php thus eliminating the possibility of upgrading to future versions.
Depends on what you want to do. Someone created a user registration system, because this is mostly implemented with PHP and they can create their own registration script. It would be much more complicated if you intend to make modifications to the actual frontend. Although there are many javascript config options, this isn't really a way to add new features. The _files/plugins is just a folder where I added a few plugins. It's not a specific scheme to integrate custom plugins.
Unfortunately, the answer is no.
cwal Can your software be used for "commercial" purposes (with a license)? The license description talks about using it for "client websites and projects" but if I were to extend the functionality and use Files as the backbone for functionality of some sort of SaaS platform, is that allowed in the license? For example I create an image hosting website with specific social features, where Files is the underlying system for managing users and displaying albums (AKA folders)
You can use it for commercial purposes yes (personal license = 1 project, unlimited license = unlimited projects). That includes creating a commercial service that you can charge fees for. However, it does not allow redistributing the license key, and therefore does not allow selling or distributing an app that contains Files Gallery and a license key.
cwal Is the "Embed" license the same as the Files license? Or the Embed license is purchased separately from the Files license? Does the Embed license also have "personal" and "unlimited" licenses? Can the Embed license be used on multiple websites if connected to the same Files installation? Or can the Embed license be used on one website but connected to multiple Files installations? For example if one page uses Embed for a Files installation on a personal sever and another page uses Embed for a Files installation on a client server.
It's a separate license. Embed works with the free version of Files Gallery, so you only need the Embed license to operate Embed. However, if you also need Files Gallery premium features (for example file manager actions), a license would be required.
There hasn't really been much focus on Embed since it's release. It can inject a photo gallery into a 3rd party website, without using iframe, and that's about it. Embed only has one license type. You can use it on as many websites as you like, as long as you don't sell/distribute with the license key.
In conclusion, I think the challenge here is that Files Gallery probably isn't a great platform for customization or implementing into other applications. Thanks for your questions nevertheless!