SharePoint 2010 offers four levels of customization (L1-L4) with increasing capabilities. L1 includes out-of-the-box customizations using the browser. L2 adds SharePoint Designer 2010 for master pages, themes, and workflows. L3 includes sandboxed solutions in Visual Studio 2010 for web parts, workflows, and InfoPath forms. L4 provides full-trust farm solutions for Business Connectivity Services, workflows with code, and additional advanced customizations only for on-premises environments.

1. 5/23/2011
SharePoint 2010 Customization Levels
L1 L2 L3 L4
Out-of-the-Box (Browser) SharePoint Designer 2010 Visual Studio 2010 (Deployable Online) Visual Studio 2010 (On Prem Only)
Browser-based page editing Master pages Sandboxed Solutions (Parial-trust code) Farm-level Solutions (Full-trust code)
List and library Management Theming Client Object Model BCS (backedn LOB Integration)
Web Parts Site Templates SharePoint Web Services InfoPath Forms (Admin and Sandbox)
Workflows Declarative workflows Silverlight Web Part (.XAP files) Workflows (Custom and Decalarative)
Site Templates InfoPath Forms (Sandbox only) Visual Web Parts
Workflow Custom Activities (Sandbox) Application Pages
Ribbon Bar Custom Action Group
HideCustomAction element
Sandbox Solution Supported Content Type Binding
List Definitions Web Application-scoped features
List Instances Farm-scoped features
Onet.xml Workflows with code
WebTemplate feature elements (instead of Webtemp.xml)
Content Types/Fields
Navigation
Module/files
Feature callouts
Web Parts
Support for all Web Parts that derive from System.Web.UI.WebControls.WebParts.WebPart
Event receivers
SPItemEventReceiver
SPListEventReceiver
SPWebEventReceiver
Custom actions
Declarative workflows
With Visual Studio Power Tools
Visual Web Parts
References: hƩp://www.sharepointpromag.com/content/content/129186/Fox_Table1.JPG
http://www.sharepointpromag.com/content/content/129688/Table%201.JPG
http://msdn.microsoft.com/en-us/library/ee231562.aspx
Brendon Schwartz
http://blogs.sharepointguys.com/brendon