osCommerce v4 will come with a number of payment methods. It is being debated now which ones will be included into the "box" installation and which ones will be moved to be apps (free or paid), so the list below is to be confirmed.
Payment methods split in two major groups - online and offline.
Each sale channel (front end or virtual) may have a number of specific payment methods assigned to it; one and the same payment method can be assigned to more than one sale channel, and in that case the settings of such payment method can be made completely different for different sales channels.
Payment methods (same as shipping methods) can be present in the system but be not installed, or activated, or linked to a particular country or region. In that case they will appear in the back end (corresponding filters to be set) but not in the front end.
Payment methods can be also linked to particular customer groups only.
Payment methods can be made available to particular parts of the system. So there could be payment methods only available to wholesale clients, or only to back end users for example.
Offline payment methods are currently as follows:
COD (Cash on Delivery)
COD for POS
Credit Card for POS
Purchase Order (likely to be used by customers paying on account)
Offline payments (general offline payment method)
It is possible to easily extend this list and add more offline payment methods, they mostly act as placeholders and are mostly used to record the fact of payment and then run analytics on what methods customers used to pay.
Online payment methods are currently as follows (in no particular order):
PayPal (various implementations, including Express checkout)
Klarna checkout (likely + online finance!, to be confirmed)
Recurly (to be confirmed)
Pay by Amazon (to be confirmed)
Humm by FlexiFi (online finance!)
Global Payments (former Realex)
It is very likely that some of the above modules will be moved to a new category Online Finance before the release of osCommerce v4
Stripe is also available as a payment module!, thanks @14steve14 for pointing this out!
I think likely as @Hotclutch
I mean... Some people doesn't need 120 payment methods in a single e-Commerce shop.
That may be more efficient to gather them 1 by 1 when we have needs for.
Anyway, all of additional payment methods (which was involved to be included in core) would be aswell free as... external plug-in.
The result to have unwanted payment methods can also lead to security breach (even not-installed/not-enabled, due to the fact files will be here aswell) (I mean since modules aren't all useful for payment/shipping stuff, why include them into main OSCommerce 4 release (and furthermore releases)).
Just my thoughts on it, but when I develop an OSCommerce site, I only have the use for 3-4 payments methods.
Perhaps, for a GIIIIIIANT site, ... it will be useful, but not for a small one, but also perhaps I'm wrong.. ?
Anyway, I love what I see in term of ergonomy and features! Keep up that excellent job on OSCommerce future