(EDIT: replaced beta URL with public release URL)
The benefits are obvious: someone new to using ROM hacks no longer needs to be told to also download a patcher (typically Lunar IPS)… with additional instructions in case he may be using a non-Windows platform, and with the potential problem of the program no longer running on current systems, especially in the case of the Mac: this happened for PowerPC-compiled patchers, it could happen again. Just point him at JPS, and he will be good to go (ideally, anyway; there are currently limitations, as we'll see). Furthermore, being web-based means you are, by default, using the latest version without any additional effort. And you do not lose the benefit of being able to use the software while offline: after having been loaded once, your browser will be able to reload it while cut off from the Net (of course, you should put it in a bookmark to make sure you can recall the URL without needing to go through this page); in fact, even if I were to let my domain expire and no one could access the URL anymore, your browser would keep the latest version it obtained and allow you to keep using JPS.
All this is made possible by recent advances in browsers, particularly in the domain of file manipulation and offline use support.
So recent, in fact, that unfortunately not all browsers have the necessary support, and I am sad to say that, regardless of my efforts, Safari and Internet Explorer are not supported
*. Any reasonably recent version of Firefox or Chrome (both of which update automatically anyway), as well as any version of Opera starting with Opera 15 is supported; Safari is supported starting with Technology Preview 19 or Safari 10.1, and Edge starting with version 13 normally.
Also, while I have subjected JPS to about 100 patches downloaded from this site to validate its behavior**, and fixed the most egregious issues (one of which crashed Firefox. Yes, taking down all your other Firefox tabs), there remains a few know issues. The most notable one is that, on Firefox, some patches (just one in the ~100 I tested), once applied, cannot be downloaded: that is, clicking the download link does absolutely nothing***. The only other known limitation is truncation support: it is not implemented yet.****
But even with the remaining issues, it is in good enough state that I now declare it in open beta. Use it
, prod it, test it, abuse it, send feedback, or not, go ahead. Obviously, new beta versions will be deployed at the same URL and you will automatically get them.
And for the anecdote, yes, this is what I asked IPS test files for in the other topic
. I intend to release its source code once it is out of beta.
*the reason being that neither browser supports downloading generated files (called blobs) with the download attribute
. In the case of Safari, I requested the functionality in http://www.openradar.me/23550189
no answer so far the request was marked as a duplicate of a previous request, so at least they are not rejecting the idea outright
it has now been implemented, and after additional issues were fixed, Safari can now run JPS starting with technology Preview 19.
**including checking the output is identical to what Lunar IPS gives for the same patch
***logged in the Firefox bug tracker at https://bugzilla.mozilla.org/show_bug.cgi?id=1224870
****what is not a limitation, however, is the lack of support for creating patches; creation of IPS patches will never be supported