Most of these resources aren't official copies, so be cautious in how you use them, however, they can be excellent resources for getting eyes on opinions if you have limited resources and just want to see the opinion before making any further decisions/purchases.
Google Scholar has copies of opinions from all of Alabama's Appellate Courts back to 1950. To find them, make sure to switch the search terms from Articles to Case Law, then select Alabama Courts. You could also use Select Courts to see a list of all available jurisdictions, where you should find all available Alabama jurisdictions.
CourtListener hosts cases from all levels of Alabama Appellate Courts. They have copies of opinions from:
To find opinions, first click Select Jurisdiction, which should pull up a list of all available jurisdictions.
It will automatically default to having all jurisdictions selected, so just clear all and then select the State tab to see all available Alabama courts.
The Alabama Judicial System website has a link to slip opinions for each Alabama Appellate Court.
You can use FindLaw to find copies of opinions from all Alabama Appellate Courts.
Caselaw Access Project scanned the entirety of Harvard Law School's Law Library's physical collection of American case law and made it machine-readable. They don't provide access to everything, however, it appears to be quite a good resource for many historical opinions.
Most of these resources are only available by subscription, however, if you don't have access on your own, you can come in and use the monitor at the circulation desk for limited access to Westlaw and Lexis.
In Alabama State Materials, you can find both reported and unreported cases from:
Within the Alabama State Materials, you can find:
If you're looking for predominately historical materials, HeinOnline is an excellent place to start. Within State Reports: A Historical Archive, you can find opinions from Alabama, dating back to 1820.