Index: kernel-impl/src/main/java/org/sakaiproject/tool/impl/ActiveToolComponent.java
===================================================================
--- kernel-impl/src/main/java/org/sakaiproject/tool/impl/ActiveToolComponent.java	(revision 120844)
+++ kernel-impl/src/main/java/org/sakaiproject/tool/impl/ActiveToolComponent.java	(working copy)
@@ -72,6 +72,8 @@
 	private static Log M_log = LogFactory.getLog(ActiveToolComponent.class);
 
 	public static final String TOOL_PORTLET_CONTEXT_PATH = "portlet-context";
+	static final String TOOL_CATEGORIES_PREFIX = "tool.categories.";
+	static final String TOOL_CATEGORIES_APPEND_PREFIX = TOOL_CATEGORIES_PREFIX+"append.";
 
 	// private ResourceLoader toolProps = null;
 
@@ -369,6 +371,28 @@
 			}
 		}
 
+		// KNL-1031 - Override OR Add additional categories from sakai.properties
+		String[] categoriesArray = serverConfigurationService().getStrings(TOOL_CATEGORIES_PREFIX+tool.getId());
+		if (categoriesArray != null) {
+		    // override the set of categories
+		    categories.clear();
+		    for (String category: categoriesArray) {
+		        if (StringUtils.isNotBlank(category)) {
+		            categories.add(category);
+		        }
+		    }
+		} else {
+		    categoriesArray = serverConfigurationService().getStrings(TOOL_CATEGORIES_APPEND_PREFIX+tool.getId());
+		    if (categoriesArray != null) {
+		        // add categories instead of overriding
+		        for (String category: categoriesArray) {
+		            if (StringUtils.isNotBlank(category)) {
+		                categories.add(category);
+		            }
+		        }
+		    }
+		}
+
 		// set the tool's collected values
 		tool.setRegisteredConfig(finalConfig, mutableConfig);
 		tool.setCategories(categories);