diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index ced477eeeec..7b35c5e0d65 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -702,9 +702,9 @@ namespace ts {
     /**
      *  List of supported extensions in order of file resolution precedence.
      */
-    export const supportedExtensions = [".ts", ".d.ts"];
+    export const supportedExtensions = [".tsx", ".ts", ".d.ts"];
 
-    const extensionsToRemove = [".d.ts", ".ts", ".js"];
+    const extensionsToRemove = [".d.ts", ".ts", ".js", ".tsx", ".jsx"];
     export function removeFileExtension(path: string): string {
         for (let ext of extensionsToRemove) {
             if (fileExtensionIs(path, ext)) {
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index f9a2fa3b7b4..d78d38d5ba7 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -48,6 +48,7 @@ namespace ts {
         SemicolonToken,
         CommaToken,
         LessThanToken,
+        LessThanSlashToken,
         GreaterThanToken,
         LessThanEqualsToken,
         GreaterThanEqualsToken,
@@ -217,6 +218,8 @@ namespace ts {
         ClassExpression,
         OmittedExpression,
         ExpressionWithTypeArguments,
+        AsExpression,
+
         // Misc
         TemplateSpan,
         SemicolonClassElement,
@@ -265,6 +268,16 @@ namespace ts {
         // Module references
         ExternalModuleReference,
 
+        //JSX
+        JsxElement,
+        JsxSelfClosingElement,
+        JsxOpeningElement,
+        JsxText,
+        JsxClosingElement,
+        JsxAttribute,
+        JsxSpreadAttribute,
+        JsxExpression,
+
         // Clauses
         CaseClause,
         DefaultClause,
@@ -396,6 +409,17 @@ namespace ts {
         HasAggregatedChildData = 1 << 8
     }
 
+    export const enum JsxFlags {
+        None = 0,
+        IntrinsicNamedElement = 1 << 0,
+        IntrinsicIndexedElement = 1 << 1,
+        ClassElement = 1 << 2,
+        UnknownElement = 1 << 3,
+
+        IntrinsicElement = IntrinsicNamedElement | IntrinsicIndexedElement
+    }
+
+
     /* @internal */
     export const enum RelationComparisonResult {
         Succeeded = 1, // Should be truthy
@@ -799,11 +823,66 @@ namespace ts {
 
     export type CallLikeExpression = CallExpression | NewExpression | TaggedTemplateExpression;
 
+    export interface AsExpression extends Expression {
+        expression: Expression;
+        type: TypeNode;
+    }
+
     export interface TypeAssertion extends UnaryExpression {
         type: TypeNode;
         expression: UnaryExpression;
     }
 
+    export type AssertionExpression = TypeAssertion | AsExpression;
+
+    /// A JSX expression of the form <TagName attrs>...</TagName>
+    export interface JsxElement extends PrimaryExpression {
+        openingElement: JsxOpeningElement;
+        children: NodeArray<JsxChild>;
+        closingElement: JsxClosingElement;
+    }
+
+    /// The opening element of a <Tag>...</Tag> JsxElement
+    export interface JsxOpeningElement extends Expression {
+        _openingElementBrand?: any;
+        tagName: EntityName;
+        attributes: NodeArray<JsxAttribute | JsxSpreadAttribute>;
+    }
+
+    /// A JSX expression of the form <TagName attrs />
+    export interface JsxSelfClosingElement extends PrimaryExpression, JsxOpeningElement {
+        _selfClosingElementBrand?: any;
+    }
+
+    /// Either the opening tag in a <Tag>...</Tag> pair, or the lone <Tag /> in a self-closing form
+    export type JsxOpeningLikeElement = JsxSelfClosingElement | JsxOpeningElement;
+
+    export interface JsxAttribute extends Node {
+        name: Identifier;
+        /// JSX attribute initializers are optional; <X y /> is sugar for <X y={true} />
+        initializer?: Expression;
+    }
+
+    export interface JsxSpreadAttribute extends Node {
+        expression: Expression;
+    }
+
+    export interface JsxClosingElement extends Node {
+        tagName: EntityName;
+    }
+
+    export interface JsxExpression extends Expression {
+        expression?: Expression;
+    }
+
+    export interface JsxText extends Node {
+        _jsxTextExpressionBrand: any;
+        /// Used by the emitter to avoid recomputation
+        formattedReactText?: string;
+    }
+
+    export type JsxChild = JsxText | JsxExpression | JsxElement | JsxSelfClosingElement;
+
     export interface Statement extends Node {
         _statementBrand: any;
     }
@@ -1144,6 +1223,7 @@ namespace ts {
         amdDependencies: {path: string; name: string}[];
         moduleName: string;
         referencedFiles: FileReference[];
+        isTSXFile: boolean;
 
         /**
          * lib.d.ts should have a reference comment like
@@ -1323,6 +1403,9 @@ namespace ts {
         getAliasedSymbol(symbol: Symbol): Symbol;
         getExportsOfModule(moduleSymbol: Symbol): Symbol[];
 
+        getJsxElementAttributesType(elementNode: JsxOpeningLikeElement): Type;
+        getJsxIntrinsicTagNames(): Symbol[];
+
         // Should not be called directly.  Should only be accessed through the Program instance.
         /* @internal */ getDiagnostics(sourceFile?: SourceFile): Diagnostic[];
         /* @internal */ getGlobalDiagnostics(): Diagnostic[];
@@ -1603,6 +1686,7 @@ namespace ts {
         assignmentChecks?: Map<boolean>;  // Cache of assignment checks
         hasReportedStatementInAmbientContext?: boolean;  // Cache boolean if we report statements in ambient context
         importOnRightSide?: Symbol;       // for import declarations - import that appear on the right side
+        jsxFlags?: JsxFlags;              // flags for knowning what kind of element/attributes we're dealing with
     }
 
     export const enum TypeFlags {
@@ -1834,6 +1918,7 @@ namespace ts {
         help?: boolean;
         inlineSourceMap?: boolean;
         inlineSources?: boolean;
+        jsx?: JsxEmit;
         listFiles?: boolean;
         locale?: string;
         mapRoot?: string;
@@ -1877,6 +1962,12 @@ namespace ts {
         System = 4,
     }
 
+    export const enum JsxEmit {
+        None = 0,
+        Preserve = 1,
+        React = 2
+    }
+
     export const enum NewLineKind {
         CarriageReturnLineFeed = 0,
         LineFeed = 1,
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index ee75454ad93..7ec599babbc 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -169,13 +169,13 @@ namespace ts {
         return skipTrivia((sourceFile || getSourceFileOfNode(node)).text, node.decorators.end);        
     }
 
-    export function getSourceTextOfNodeFromSourceFile(sourceFile: SourceFile, node: Node): string {
+    export function getSourceTextOfNodeFromSourceFile(sourceFile: SourceFile, node: Node, includeTrivia = false): string {
         if (nodeIsMissing(node)) {
             return "";
         }
 
         let text = sourceFile.text;
-        return text.substring(skipTrivia(text, node.pos), node.end);
+        return text.substring(includeTrivia ? node.pos : skipTrivia(text, node.pos), node.end);
     }
 
     export function getTextOfNodeFromSourceText(sourceText: string, node: Node): string {
@@ -186,8 +186,8 @@ namespace ts {
         return sourceText.substring(skipTrivia(sourceText, node.pos), node.end);
     }
 
-    export function getTextOfNode(node: Node): string {
-        return getSourceTextOfNodeFromSourceFile(getSourceFileOfNode(node), node);
+    export function getTextOfNode(node: Node, includeTrivia = false): string {
+        return getSourceTextOfNodeFromSourceFile(getSourceFileOfNode(node), node, includeTrivia);
     }
 
     // Add an extra underscore to identifiers that start with two underscores to avoid issues with magic names like '__proto__'
@@ -850,6 +850,7 @@ namespace ts {
             case SyntaxKind.CallExpression:
             case SyntaxKind.NewExpression:
             case SyntaxKind.TaggedTemplateExpression:
+            case SyntaxKind.AsExpression:
             case SyntaxKind.TypeAssertionExpression:
             case SyntaxKind.ParenthesizedExpression:
             case SyntaxKind.FunctionExpression:
@@ -866,6 +867,8 @@ namespace ts {
             case SyntaxKind.TemplateExpression:
             case SyntaxKind.NoSubstitutionTemplateLiteral:
             case SyntaxKind.OmittedExpression:
+            case SyntaxKind.JsxElement:
+            case SyntaxKind.JsxSelfClosingElement:
             case SyntaxKind.YieldExpression:
                 return true;
             case SyntaxKind.QualifiedName:
@@ -912,7 +915,8 @@ namespace ts {
                         return (forInStatement.initializer === node && forInStatement.initializer.kind !== SyntaxKind.VariableDeclarationList) ||
                             forInStatement.expression === node;
                     case SyntaxKind.TypeAssertionExpression:
-                        return node === (<TypeAssertion>parent).expression;
+                    case SyntaxKind.AsExpression:
+                        return node === (<AssertionExpression>parent).expression;
                     case SyntaxKind.TemplateSpan:
                         return node === (<TemplateSpan>parent).expression;
                     case SyntaxKind.ComputedPropertyName:
@@ -1886,6 +1890,8 @@ namespace ts {
                 case SyntaxKind.ElementAccessExpression:
                 case SyntaxKind.NewExpression:
                 case SyntaxKind.CallExpression:
+                case SyntaxKind.JsxElement:
+                case SyntaxKind.JsxSelfClosingElement:
                 case SyntaxKind.TaggedTemplateExpression:
                 case SyntaxKind.ArrayLiteralExpression:
                 case SyntaxKind.ParenthesizedExpression: