There has been a lot of speculation and confusion around sandbox solution being deprecated in SharePoint 2013. But finally, the SharePoint team has clarified that no-code sandboxed solutions (NCSS) are very much supported.
Following is the update from the SharePoint team. In conclusion, we have some clear message coming across from the production team w.r.t sandbox solution development.
While developing sandbox solutions that contain only declarative mark-up and JavaScript — which we call no-code sandboxed solutions (NCSS) — is still viable, we have deprecated the use of custom managed code within the sandbox solution. We have introduced the new SharePoint app model as a replacement to those scenarios that required the use of managed code. The app model decouples the SharePoint core product from the app runtime, and this enables much more flexibility and gives you the ability to run the code in the environment of your choice. We realize that our customers have made investments in coded sandboxed solutions and we will phase them out responsibly. Existing coded sandboxed solutions will continue to work in on-premises SharePoint farms for the foreseeable future. Given the dynamic nature of online services, we will determine support needs for coded sandboxed solutions in SharePoint Online based on customer demand. NCSSs continue to be supported. All future investments will go to making the new SharePoint app model richer and more powerful. Accordingly, we recommend that all new development should use the new app model whenever possible. In scenarios where you have to develop a farm solution or coded sandboxed solution, we recommend that you design it so that it can easily evolve toward a more loosely coupled development model
Sandbox Solution Development – Conclusion
| Sandbox solution without managed code (i.e having only declarative mark-up and JavaScript) | Supported |
| Sandbox solution with managed code | Not Supported (Use the SharePoint App Model instead) |
Reference - SharePoint Dev Blog
