diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ITool.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ITool.java
index 4199020096f..1eaed24c145 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ITool.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ITool.java
@@ -12,7 +12,6 @@ package org.eclipse.cdt.managedbuilder.core;
 
 import java.util.List;
 
-import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IPath;
 
 import org.eclipse.cdt.core.settings.model.extension.CLanguageData;
@@ -498,45 +497,12 @@ public interface ITool extends IBuildObject, IHoldsOptions {
 	 */
 	public void setCommandLinePattern(String pattern);
 	
-	/**
-	 * Returns the plugin.xml element of the commandLineGenerator extension or <code>null</code> if none. 
-	 *  
-	 * @return IConfigurationElement
-	 * 
-	 * @deprecated - use getCommandLineGenerator
-	 */
-	public IConfigurationElement getCommandLineGeneratorElement();
-	
-	/**
-	 * Sets the CommandLineGenerator plugin.xml element
-	 * 
-	 * @param element
-	 * @deprecated
-	 */
-	public void setCommandLineGeneratorElement(IConfigurationElement element);
-	
 	/**
 	 * Returns the command line generator specified for this tool
 	 * @return IManagedCommandLineGenerator
 	 */
 	public IManagedCommandLineGenerator getCommandLineGenerator();
 	
-	/**
-	 * Returns the plugin.xml element of the dependencyGenerator extension or <code>null</code> if none. 
-	 *  
-	 * @return IConfigurationElement
-	 * @deprecated - use getDependencyGeneratorForExtension or IInputType#getDependencyGenerator method
-	 */
-	public IConfigurationElement getDependencyGeneratorElement();
-	
-	/**
-	 * Sets the DependencyGenerator plugin.xml element
-	 * 
-	 * @param element
-	 * @deprecated 
-	 */
-	public void setDependencyGeneratorElement(IConfigurationElement element);
-	
 	/**
 	 * Returns a class instance that implements an interface to generate 
 	 * source-level dependencies for the tool specified in the argument. 
@@ -747,22 +713,12 @@ public interface ITool extends IBuildObject, IHoldsOptions {
 	
 	IResourceInfo getParentResourceInfo();
 	
-/*	IInputType setSourceContentTypeIds(IInputType type, String[] ids);
-
-	IInputType setHeaderContentTypeIds(IInputType type, String[] ids);
-	
-	IInputType setSourceExtensionsAttribute(IInputType type, String[] extensions);
-
-	IInputType setHeaderExtensionsAttribute(IInputType type, String[] extensions);
-*/
 	IInputType getEditableInputType(IInputType base);
 	
 	IOutputType getEditableOutputType(IOutputType base);
 	
 	boolean isEnabled();
 	
-//	boolean isReal();
-	
 	boolean supportsBuild(boolean managed);
 	
 	boolean matches(ITool tool);
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ManagedBuildManager.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ManagedBuildManager.java
index 71f967e20df..0a0106663df 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ManagedBuildManager.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ManagedBuildManager.java
@@ -223,6 +223,8 @@ public class ManagedBuildManager extends AbstractCExtension {
 	private static Map extensionOutputTypeMap;
 	// Targets defined in the manifest files (CDT V2.0 object model)
 	private static Map extensionTargetMap;
+	
+	
 	// "Selected configuraton" elements defined in the manifest files.
 	// These are configuration elements that map to objects in the internal
 	// representation of the manifest files.  For example, ListOptionValues
@@ -232,7 +234,8 @@ public class ManagedBuildManager extends AbstractCExtension {
 	// From the PDE Guide:
 	//  A configuration element, with its attributes and children, directly 
 	//  reflects the content and structure of the extension section within the 
-	//  declaring plug-in's manifest (plugin.xml) file. 
+	//  declaring plug-in's manifest (plugin.xml) file.
+	// This map has a lifecycle corresponding to the build definitions extension loading.
 	private static Map configElementMap;
 	
 //	private static List sortedToolChains;
@@ -2249,6 +2252,12 @@ public class ManagedBuildManager extends AbstractCExtension {
 		if (projectTypesLoading)
 			return;
 		projectTypesLoading = true;
+
+		
+		// scalability issue:  configElementMap does not need to live past when loading is done, so we will
+		// deallocate it upon exit with a try...finally
+		
+		try {
 		
 		//The list of the IManagedBuildDefinitionsStartup callbacks 
 		List buildDefStartupList = null;
@@ -2555,6 +2564,12 @@ public class ManagedBuildManager extends AbstractCExtension {
 		projectTypesLoaded = true;
 		
 		ToolChainModificationManager.getInstance().start();
+		
+		} // try
+		
+		finally {
+			configElementMap = null;
+		}
 	}
 	
 	private static void performAdjustments(){
@@ -3207,6 +3222,9 @@ public class ManagedBuildManager extends AbstractCExtension {
 	}
 
 	private static Map getConfigElementMap() {
+		if(!projectTypesLoading)
+			throw new IllegalStateException();
+		
 		if (configElementMap == null) {
 			configElementMap = new HashMap();
 		}
@@ -3214,8 +3232,9 @@ public class ManagedBuildManager extends AbstractCExtension {
 	}
 	
 	/**
-	 * This method public for implementation reasons.  Not intended for use 
+	 * @noreference This method public for implementation reasons.  Not intended for use 
 	 * by clients.
+	 *
 	 */
 	public static void putConfigElement(IBuildObject buildObj, IManagedConfigElement configElement) {
 		getConfigElementMap().put(buildObj, configElement);
@@ -3229,7 +3248,7 @@ public class ManagedBuildManager extends AbstractCExtension {
 	}
 
 	/**
-	 * This method public for implementation reasons.  Not intended for use 
+	 * @noreference This method public for implementation reasons.  Not intended for use 
 	 * by clients.
 	 */
 	public static IManagedConfigElement getConfigElement(IBuildObject buildObj) {
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/HoldsOptions.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/HoldsOptions.java
index 29c56380404..58f5e3a4b5b 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/HoldsOptions.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/HoldsOptions.java
@@ -12,6 +12,8 @@ package org.eclipse.cdt.managedbuilder.internal.core;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
@@ -64,7 +66,6 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 	private Vector<String> categoryIds;
 	private Map<String, IOptionCategory> categoryMap;
 	private List<IOptionCategory> childOptionCategories;
-	private Vector<Option> optionList;
 	private Map<String, Option> optionMap;
 	//  Miscellaneous
 	private boolean isDirty = false;
@@ -97,8 +98,8 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 		//        found on an non-extension tools
 		
 		boolean copyIds = id.equals(source.id);
-		if (source.optionList != null) {
-			Iterator<Option> iter = source.getOptionList().listIterator();
+		if (source.optionMap != null) {
+			Iterator<Option> iter = source.getOptionCollection().iterator();
 			while (iter.hasNext()) {
 				Option option = iter.next();
 				int nnn = ManagedBuildManager.getRandomNumber();
@@ -123,7 +124,7 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 	}
 	
 	void copyNonoverriddenSettings(HoldsOptions ho){
-		if (ho.optionList == null || ho.optionList.size() == 0)
+		if (ho.optionMap == null || ho.optionMap.size() == 0)
 			return;
 		
 		IOption options[] = getOptions();
@@ -209,8 +210,8 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 			}
 		}
 		
-		List<Option> optionElements = getOptionList();
-		Iterator<Option> iter2 = optionElements.listIterator();
+		Collection<Option> optionElements = getOptionCollection();
+		Iterator<Option> iter2 = optionElements.iterator();
 		while (iter2.hasNext()) {
 			Option option = iter2.next();
 			ICStorageElement optionElement = element.createChild(OPTION);
@@ -239,7 +240,7 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 	 * @see org.eclipse.cdt.managedbuilder.core.IHoldsOptions#createOptions(IHoldsOptions)
 	 */
 	public void createOptions(IHoldsOptions superClass) {
-		Iterator<Option> iter = ((HoldsOptions)superClass).getOptionList().listIterator();
+		Iterator<Option> iter = ((HoldsOptions)superClass).getOptionCollection().iterator();
 		while (iter.hasNext()) {
 			Option optionChild = (Option) iter.next();
 			int nnn = ManagedBuildManager.getRandomNumber();
@@ -256,7 +257,6 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 			return;
 //			throw new IllegalArgumentException();
 		
-		getOptionList().remove(option);
 		getOptionMap().remove(option.getId());
 		setDirty(true);
 		setRebuildState(true);
@@ -276,11 +276,12 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 			options = superClass.getOptions();
 		}
 		// Our options take precedence.
-		Vector<Option> ourOpts = getOptionList();
+		Collection<Option> ourOpts = getOptionCollection();
+		Iterator<Option> iter = ourOpts.iterator();
 		if (options != null) {
-			for (int i = 0; i < ourOpts.size(); i++) {
+			while(iter.hasNext()) {
 				int j = options.length;
-				IOption ourOpt = (IOption)ourOpts.get(i);
+				IOption ourOpt = iter.next();
 				if (ourOpt.getSuperClass() != null) {
 					String matchId = ourOpt.getSuperClass().getId();
 					search:
@@ -434,7 +435,6 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 	 * @param option
 	 */
 	public void addOption(Option option) {
-		getOptionList().add(option);
 		getOptionMap().put(option.getId(), option);
 	}
 	/* (non-Javadoc)
@@ -450,11 +450,11 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 	/* (non-Javadoc)
 	 * Memory-safe way to access the list of options
 	 */
-	private Vector<Option> getOptionList() {
-		if (optionList == null) {
-			optionList = new Vector<Option>();
-		}
-		return optionList;
+	private Collection<Option> getOptionCollection() {
+		// no need to store all the options twice, get them out of the map
+		if(optionMap != null)
+			return optionMap.values();
+		else return Collections.emptyList();
 	}
 	
 	/* (non-Javadoc)
@@ -502,7 +502,7 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 		if (isDirty) 
 			return true;
 		
-		for (Option option : getOptionList())
+		for (Option option : getOptionCollection())
 			if (option.isDirty()) 
 				return true;
 		
@@ -517,7 +517,7 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 		this.isDirty = isDirty;
 		// Propagate "false" to the children
 		if (!isDirty) {
-			for (Option option : getOptionList())
+			for (Option option : getOptionCollection())
 				if(!option.isExtensionElement())
 					option.setDirty(false);
 		}
@@ -531,7 +531,7 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 		if (!resolved) {
 			resolved = true;
 			//  Call resolveReferences on our children
-			for (Option current : getOptionList()) {
+			for (Option current : getOptionCollection()) {
 				current.resolveReferences();
 			}
 			// Somewhat wasteful, but use the vector to retrieve the categories in proper order
@@ -638,7 +638,7 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 			return true;
 		
 		// Otherwise see if any options need saving
-		for (Option option : getOptionList())
+		for (Option option : getOptionCollection())
 			if (option.needsRebuild()) 
 				return true;
 		
@@ -653,7 +653,7 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 		
 		// Propagate "false" to the children
 		if (!rebuildState)
-			for (Option option : getOptionList())
+			for (Option option : getOptionCollection())
 				if(!option.isExtensionElement())
 					option.setRebuildState(false);
 	}
@@ -754,8 +754,8 @@ public abstract class HoldsOptions extends BuildObject implements IHoldsOptions,
 		if(superClass == null)
 			return true;
 		
-		if(optionList != null && optionList.size() != 0){
-			for(Option option : optionList)
+		if(optionMap != null && optionMap.size() != 0){
+			for(Option option : getOptionCollection())
 				if(option.hasCustomSettings())
 					return true;
 		}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Tool.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Tool.java
index 1916a7466a3..82b7306f99f 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Tool.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Tool.java
@@ -434,10 +434,18 @@ public class Tool extends HoldsOptions implements ITool, IOptionCategory, IMatch
        	supportsManagedBuild = tool.supportsManagedBuild; 
 
 
-		commandLineGeneratorElement = tool.commandLineGeneratorElement; 
-		commandLineGenerator = tool.commandLineGenerator; 
-		dependencyGeneratorElement = tool.dependencyGeneratorElement; 
-		dependencyGenerator = tool.dependencyGenerator; 
+		commandLineGenerator = tool.commandLineGenerator;
+		if(commandLineGenerator == null) {
+			// only need XML if the generator hasn't been created yet
+			commandLineGeneratorElement = tool.commandLineGeneratorElement; 
+		}
+		
+		dependencyGenerator = tool.dependencyGenerator;
+		if(dependencyGenerator == null) {
+			// only need XML if the generator hasn't been created yet
+			dependencyGeneratorElement = tool.dependencyGeneratorElement; 
+		}
+		
 		pathconverterElement = tool.pathconverterElement ;
 		optionPathConverter = tool.optionPathConverter ;
 		
@@ -562,19 +570,31 @@ public class Tool extends HoldsOptions implements ITool, IOptionCategory, IMatch
 		if(supportsManagedBuild == null)
 			supportsManagedBuild = tool.supportsManagedBuild; 
 
-
-		if(commandLineGeneratorElement == null)
-			commandLineGeneratorElement = tool.commandLineGeneratorElement;
-		if(commandLineGenerator == null)
+		if(commandLineGenerator == null) {
 			commandLineGenerator = tool.commandLineGenerator;
-		if(dependencyGeneratorElement == null)
-			dependencyGeneratorElement = tool.dependencyGeneratorElement;
-		if(dependencyGenerator == null)
+			// only copy the generator element if we don't already have a generator
+			if(commandLineGenerator == null && commandLineGeneratorElement == null)
+				commandLineGeneratorElement = tool.commandLineGeneratorElement;
+		}
+		
+		if(dependencyGenerator == null) {
 			dependencyGenerator = tool.dependencyGenerator;
-		if(pathconverterElement == null)
-			pathconverterElement = tool.pathconverterElement ;
-		if(optionPathConverter == null)
+			
+			// only copy the generator element if we don't already have a generator
+			if(dependencyGenerator == null) {
+				if(dependencyGeneratorElement == null)
+					dependencyGeneratorElement = tool.dependencyGeneratorElement;
+			}
+		}
+		
+		if(optionPathConverter == null) {
 			optionPathConverter = tool.optionPathConverter ;
+			
+			if(optionPathConverter == null) {
+				if(pathconverterElement == null)
+					pathconverterElement = tool.pathconverterElement ;
+			}
+		}
 		
 		if(envVarBuildPathList == null && tool.envVarBuildPathList != null)
 			envVarBuildPathList = new ArrayList<IEnvVarBuildPath>(tool.envVarBuildPathList);
@@ -2089,6 +2109,7 @@ public class Tool extends HoldsOptions implements ITool, IOptionCategory, IMatch
 			try {
 				if (element.getAttribute(COMMAND_LINE_GENERATOR) != null) {
 					commandLineGenerator = (IManagedCommandLineGenerator) element.createExecutableExtension(COMMAND_LINE_GENERATOR);
+					commandLineGeneratorElement = null; // no longer needed now that we've created one
 					return commandLineGenerator;
 				}
 			} catch (CoreException e) {}
@@ -2143,7 +2164,7 @@ public class Tool extends HoldsOptions implements ITool, IOptionCategory, IMatch
 	 * @see org.eclipse.cdt.managedbuilder.core.ITool#setDependencyGeneratorElement(String)
 	 * @deprecated
 	 */
-	public void setDependencyGeneratorElement(IConfigurationElement element) {
+	private void setDependencyGeneratorElement(IConfigurationElement element) {
 		dependencyGeneratorElement = element;
 		setDirty(true);
 	}
@@ -2165,8 +2186,10 @@ public class Tool extends HoldsOptions implements ITool, IOptionCategory, IMatch
 				if (element.getAttribute(DEP_CALC_ID) != null) {
 					dependencyGenerator = (IManagedDependencyGeneratorType) element.createExecutableExtension(DEP_CALC_ID);
 					if (dependencyGenerator != null) {
-						if (dependencyGenerator instanceof IManagedDependencyGenerator)
+						if (dependencyGenerator instanceof IManagedDependencyGenerator) {
+							dependencyGeneratorElement = null; // no longer needed now that we've created one
 							return (IManagedDependencyGenerator)dependencyGenerator;
+						}
 						else
 							return null;
 					}
@@ -2789,7 +2812,9 @@ public class Tool extends HoldsOptions implements ITool, IOptionCategory, IMatch
 				IToolChain toolchain = (IToolChain) getParent();
 				optionPathConverter = toolchain.getOptionPathConverter();
 			}
-		}		
+		}
+		
+		pathconverterElement = null; // discard now that we've created one
 		return optionPathConverter ;
 	}