diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index c2c320a4..35d84c14 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -8,9 +8,9 @@ jstime is a minimal and performant JavaScript runtime built on top of the V8 Jav
 
 - **`jstime_core`** (`core/`): The core runtime library that wraps V8 and provides JavaScript APIs
   - Built-in APIs organized by standards:
-    - **WHATWG**: console, timers, fetch, URL, events (Event/EventTarget), base64, structured clone, microtask queue
-    - **W3C**: performance
-    - **Node.js compatible**: file system (fs/promises)
+    - **WHATWG**: console, timers, fetch, URL, events (Event/EventTarget), base64, structured clone, microtask queue, streams, text encoding
+    - **W3C**: performance, crypto (Web Cryptography API subset)
+    - **Node.js compatible**: file system (fs/promises), process
   - Module loading system with ES modules and JSON modules support
   - Event loop implementation for async operations
   - WebAssembly support via V8
@@ -48,6 +48,8 @@ jstime is a minimal and performant JavaScript runtime built on top of the V8 Jav
 - **urlencoding** (2.1): URL encoding/decoding utilities
 - **rustc-hash** (2.1): Fast non-cryptographic hashing for module maps
 - **filetime** (0.2): File timestamp manipulation for fs API
+- **ring** (0.17): Cryptographic operations for crypto API
+- **align-data** (0.1.0): Data alignment utilities
 - **lazy_static** (1.5.0): Lazy static initialization
 - **rustyline** (17.0.2): REPL implementation with line editing (in cli crate)
 - **structopt** (0.3.26): CLI argument parsing (in cli crate)
@@ -94,12 +96,19 @@ Built-in APIs are located in `core/src/builtins/` and organized by standards bod
 - **base64_impl.rs / base64.js**: atob() and btoa() for base64 encoding/decoding
 - **structured_clone_impl.rs / structured_clone.js**: structuredClone() for deep cloning
 - **queue_microtask_impl.rs / queue_microtask.js**: queueMicrotask()
+- **streams_impl.rs / streams.js**: ReadableStream, WritableStream, TransformStream
+- **text_encoding_impl.rs / text_encoding.js**: TextEncoder and TextDecoder for UTF-8
 
 **W3C Standards** (`w3c/`):
 - **performance_impl.rs / performance.js**: performance.now() and performance.timeOrigin
+- **crypto_impl.rs / crypto.js**: crypto.getRandomValues(), crypto.randomUUID(), crypto.subtle.digest()
 
 **Node.js Compatible** (`node/`):
 - **fs_impl.rs / fs.js**: File system API (node:fs/promises module)
+- **process_impl.rs / process.js**: process.env, process.argv, process.cwd(), process.exit(), process.stdout, process.stderr, process.stdin
+
+**Polyfills** (`polyfills/`):
+- **date_locale.js**: Date.prototype.toLocaleString() and related methods
 
 ### Adding New Built-ins
 
@@ -128,15 +137,18 @@ Built-in APIs are located in `core/src/builtins/` and organized by standards bod
 - **`core/tests/test_conformance_*.rs`**: WHATWG/W3C spec conformance tests
   - `test_conformance_base64.rs`: Base64 encoding (29 tests)
   - `test_conformance_console.rs`: Console API (13 tests)
-  - `test_conformance_event.rs`: Event and EventTarget (tests)
+  - `test_conformance_crypto.rs`: Crypto API (17 tests)
+  - `test_conformance_event.rs`: Event and EventTarget (33 tests)
   - `test_conformance_fetch.rs`: Fetch API (32 tests)
+  - `test_conformance_json_modules.rs`: JSON module imports (12 tests)
   - `test_conformance_performance.rs`: Performance API (19 tests)
+  - `test_conformance_streams.rs`: Streams API (26 tests)
+  - `test_conformance_structured_clone.rs`: Structured clone (21 tests)
+  - `test_conformance_text_encoding.rs`: Text Encoding API (39 tests)
   - `test_conformance_timers.rs`: Timers API (17 tests)
   - `test_conformance_url.rs`: URL API (26 tests)
   - `test_conformance_webassembly.rs`: WebAssembly API (28 tests)
-  - `test_conformance_structured_clone.rs`: Structured clone (tests)
-  - `test_conformance_json_modules.rs`: JSON module imports (tests)
-- **`core/tests/test_*.rs`**: Feature-specific tests (timers, fetch, fs, webassembly)
+- **`core/tests/test_*.rs`**: Feature-specific tests (timers, fetch, fs, process, crypto, webassembly)
 - **`core/tests/common/mod.rs`**: Shared test utilities (setup guards, helper functions)
 - **`core/tests/fixtures/`**: Test data and sample files organized by feature
 
diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index ba83341b..d0be5b6a 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -27,7 +27,7 @@ jstime is a minimal JavaScript runtime built on top of the V8 JavaScript engine.
 
 ### Technology Stack
 
-- **Language**: Rust (2021 edition)
+- **Language**: Rust (2024 edition)
 - **JavaScript Engine**: V8 (v140.2.0)
 - **Build System**: Cargo
 - **Testing**: Rust's built-in test framework
@@ -61,8 +61,9 @@ jstime is a minimal JavaScript runtime built on top of the V8 JavaScript engine.
 │  └──────────────────────────────────────────────────────┘   │
 │  ┌──────────────────────────────────────────────────────┐   │
 │  │              Built-in APIs (builtins/)               │   │
-│  │  console | timers | fetch | url | performance        │   │
-│  │  base64 | events | structured_clone | fs | wasm     │   │
+│  │  console | timers | fetch | streams | url           │   │
+│  │  performance | events | base64 | structured_clone   │   │
+│  │  text_encoding | crypto | fs | process | wasm       │   │
 │  └──────────────────────────────────────────────────────┘   │
 │  ┌──────────────────────────────────────────────────────┐   │
 │  │         Core Runtime Components                      │   │
@@ -239,21 +240,29 @@ Each API follows a two-part structure:
 - Console: Logging and debugging
 - Timers: setTimeout, setInterval
 - Performance: High-resolution timing
+- Microtask: queueMicrotask
 
 **Web APIs**:
 - Fetch: HTTP client
+- Streams: ReadableStream, WritableStream, TransformStream
 - URL: URL parsing and manipulation
 - Events: Event and EventTarget
 
 **Data APIs**:
 - Base64: Encoding and decoding
 - Structured Clone: Deep object cloning
+- Text Encoding: TextEncoder and TextDecoder
+
+**Crypto APIs**:
+- Web Crypto: getRandomValues, randomUUID, subtle.digest
 
 **System APIs**:
 - File System: Node.js-compatible fs/promises API
+- Process: Environment variables, arguments, working directory
 
 **Advanced APIs**:
 - WebAssembly: WASM module execution (via V8)
+- JSON Modules: Import JSON files as ES modules
 
 ## Module System
 
diff --git a/core/tests/CONFORMANCE_TESTS.md b/core/tests/CONFORMANCE_TESTS.md
index 1acc386f..9688be5e 100644
--- a/core/tests/CONFORMANCE_TESTS.md
+++ b/core/tests/CONFORMANCE_TESTS.md
@@ -96,6 +96,23 @@ This directory contains conformance tests for jstime's implementation of standar
   - Argument passing to timer callbacks
   - Timer ordering and execution
 
+### Event and EventTarget
+- **File**: `test_conformance_event.rs`
+- **Specification**: [DOM Standard - Events](https://dom.spec.whatwg.org/#events)
+- **Tests**: 33 tests
+- **Coverage**:
+  - `Event` constructor and properties (type, target, currentTarget, eventPhase)
+  - Event state properties (bubbles, cancelable, defaultPrevented, composed, isTrusted, timeStamp)
+  - Event methods (preventDefault, stopPropagation, stopImmediatePropagation)
+  - Event phase constants (NONE, CAPTURING_PHASE, AT_TARGET, BUBBLING_PHASE)
+  - `EventTarget` constructor
+  - Event listener registration (addEventListener)
+  - Event listener removal (removeEventListener)
+  - Event dispatching (dispatchEvent)
+  - Multiple listeners on same target
+  - Listener execution order
+  - Event propagation control
+
 ### Streams API
 - **File**: `test_conformance_streams.rs`
 - **Specification**: [WHATWG Streams Standard](https://streams.spec.whatwg.org/)
@@ -113,12 +130,71 @@ This directory contains conformance tests for jstime's implementation of standar
   - Integration with Fetch API (`Response.body`)
   - Data transformation through pipelines
 
+### Text Encoding API
+- **File**: `test_conformance_text_encoding.rs`
+- **Specification**: [WHATWG Encoding Standard](https://encoding.spec.whatwg.org/)
+- **Tests**: 39 tests
+- **Coverage**:
+  - `TextEncoder` constructor and encoding property
+  - `TextEncoder.encode()` method with UTF-8 encoding
+  - `TextEncoder.encodeInto()` method for efficient encoding
+  - `TextDecoder` constructor with encoding label support
+  - `TextDecoder` properties (encoding, fatal, ignoreBOM)
+  - `TextDecoder.decode()` method
+  - Multi-byte character encoding (2-byte, 3-byte, 4-byte UTF-8)
+  - Empty string and buffer handling
+  - Special characters and emoji encoding/decoding
+  - Buffer overflow handling in encodeInto
+  - Round-trip encoding and decoding
+
+### Structured Clone API
+- **File**: `test_conformance_structured_clone.rs`
+- **Specification**: [HTML Standard - Structured Clone](https://html.spec.whatwg.org/multipage/structured-data.html#structured-cloning)
+- **Tests**: 21 tests
+- **Coverage**:
+  - `structuredClone()` global function
+  - Primitive types (strings, numbers, booleans, null, undefined, BigInt)
+  - Object cloning with deep copy
+  - Array cloning with nested structures
+  - Date object cloning
+  - RegExp cloning with flags
+  - Map cloning
+  - Set cloning
+  - ArrayBuffer and TypedArray cloning
+  - Circular reference handling
+  - Error handling for non-cloneable types (functions, symbols)
+
+### Crypto API
+- **File**: `test_conformance_crypto.rs`
+- **Specification**: [W3C Web Cryptography API](https://w3c.github.io/webcrypto/)
+- **Tests**: 17 tests
+- **Coverage**:
+  - `crypto` global object
+  - `crypto.getRandomValues()` with various TypedArray types
+  - `crypto.randomUUID()` UUID v4 generation
+  - `crypto.subtle.digest()` with SHA-256, SHA-384, SHA-512
+  - Hash output sizes and formats
+  - Error handling for invalid algorithm names
+  - Error handling for non-TypedArray inputs
+
+### JSON Modules
+- **File**: `test_conformance_json_modules.rs`
+- **Specification**: [JSON modules proposal](https://github.com/tc39/proposal-json-modules)
+- **Tests**: 12 tests
+- **Coverage**:
+  - JSON module imports with `import` statement
+  - Default export behavior
+  - Object and array JSON imports
+  - Nested JSON structure imports
+  - Module resolution for JSON files
+  - Error handling for invalid JSON
+
 ## Running Conformance Tests
 
 To run all conformance tests:
 
 ```bash
-cargo test --test test_conformance_base64 --test test_conformance_console --test test_conformance_fetch --test test_conformance_performance --test test_conformance_streams --test test_conformance_timers --test test_conformance_url --test test_conformance_webassembly
+cargo test test_conformance_
 ```
 
 To run a specific conformance test suite:
@@ -130,15 +206,30 @@ cargo test --test test_conformance_base64
 # Console conformance tests
 cargo test --test test_conformance_console
 
+# Crypto conformance tests
+cargo test --test test_conformance_crypto
+
+# Event conformance tests
+cargo test --test test_conformance_event
+
 # Fetch conformance tests
 cargo test --test test_conformance_fetch
 
+# JSON modules conformance tests
+cargo test --test test_conformance_json_modules
+
 # Performance conformance tests
 cargo test --test test_conformance_performance
 
 # Streams conformance tests
 cargo test --test test_conformance_streams
 
+# Structured Clone conformance tests
+cargo test --test test_conformance_structured_clone
+
+# Text Encoding conformance tests
+cargo test --test test_conformance_text_encoding
+
 # Timers conformance tests
 cargo test --test test_conformance_timers
 
@@ -181,8 +272,8 @@ When adding new conformance tests:
 
 ## Total Coverage
 
-- **Total Test Files**: 8
-- **Total Tests**: 190
-- **APIs Covered**: Base64 Encoding, Console, Fetch, Performance, Streams, Timers, URL, WebAssembly
+- **Total Test Files**: 13
+- **Total Tests**: 312
+- **APIs Covered**: Base64 Encoding, Console, Crypto, Event and EventTarget, Fetch, JSON Modules, Performance, Streams, Structured Clone, Text Encoding, Timers, URL, WebAssembly
 
 All tests pass ✓
diff --git a/docs/apis/modules.md b/docs/apis/modules.md
index d64308e3..75717f84 100644
--- a/docs/apis/modules.md
+++ b/docs/apis/modules.md
@@ -5,6 +5,7 @@ This document describes the module system support in jstime, including ES Module
 ## Table of Contents
 
 - [ES Modules](#es-modules)
+- [JSON Modules](#json-modules)
 - [WebAssembly](#webassembly)
 
 
@@ -276,3 +277,83 @@ $ jstime main.js
 # The runtime automatically handles module imports
 ```
 
+## JSON Modules
+
+jstime supports importing JSON files as ES modules, following the [JSON modules proposal](https://github.com/tc39/proposal-json-modules). This allows you to import JSON data directly into your JavaScript code.
+
+**📁 Example:** See [examples/json-import-example.js](../../examples/json-import-example.js) for a complete demonstration.
+
+### Features
+
+- Import JSON files using standard `import` syntax
+- JSON data is parsed and available as the default export
+- Type-safe: imported values are standard JavaScript objects/arrays
+- Automatic file resolution with `.json` extension
+
+### Examples
+
+**data.json**
+```json
+{
+  "name": "jstime",
+  "version": "0.60.0",
+  "features": ["ES Modules", "WebAssembly", "Fetch API"]
+}
+```
+
+**app.js**
+```javascript
+// Import JSON data as the default export
+import data from './data.json';
+
+console.log(data.name);        // "jstime"
+console.log(data.version);     // "0.60.0"
+console.log(data.features[0]); // "ES Modules"
+```
+
+**config-example.js**
+```javascript
+// Import JSON configuration
+import config from './config.json';
+
+// Use the configuration data
+console.log(`App: ${config.app.name}`);
+console.log(`Environment: ${config.environment}`);
+console.log(`API URL: ${config.api.url}`);
+
+// JSON data is a regular JavaScript object
+const features = config.features.map(f => f.toUpperCase());
+console.log('Features:', features);
+```
+
+**array-example.js**
+```javascript
+// Import a JSON array
+import users from './users.json';
+
+// Work with the imported array
+users.forEach(user => {
+  console.log(`${user.name}: ${user.email}`);
+});
+
+// Filter and transform
+const admins = users.filter(u => u.role === 'admin');
+console.log(`Found ${admins.length} administrators`);
+```
+
+### Usage Notes
+
+- JSON modules are read-only: the imported data is a constant
+- The JSON file must be valid JSON (trailing commas are not allowed)
+- JSON modules use the default export pattern
+- The imported data is deeply frozen (immutable)
+
+### Running JSON Module Examples
+
+```bash
+# Run a module that imports JSON
+$ jstime app.js
+
+# The runtime automatically handles JSON module imports
+```
+
diff --git a/docs/runtime.md b/docs/runtime.md
index 043f869a..626cf3c0 100644
--- a/docs/runtime.md
+++ b/docs/runtime.md
@@ -126,17 +126,16 @@ $ jstime module.mjs
 
 ## Limitations and Future Work
 
-While jstime provides a solid foundation for JavaScript execution, there are some limitations:
+While jstime provides a solid foundation for JavaScript execution with many web standard APIs, there are some limitations:
 
-- **No file system API**: Currently no built-in API for reading/writing files
-- **No process API**: No access to environment variables or process information
-- **Limited streaming**: Fetch API doesn't support streaming response bodies
 - **No WebSocket support**: WebSocket API not yet implemented
+- **Limited DOM APIs**: No DOM APIs (this is a server-side runtime)
+- **Limited Node.js compatibility**: Only a subset of Node.js APIs are available
 
 Future enhancements being considered:
 
-- **WASI (WebAssembly System Interface)**: Support for WASI to enable WebAssembly modules to access file system and other system APIs
+- **WASI (WebAssembly System Interface)**: Support for WASI to enable WebAssembly modules to access additional system APIs
 - **Additional Web APIs**: More browser APIs as they become relevant
-- **Node.js compatibility layer**: Compatibility APIs for running Node.js code
+- **Expanded Node.js compatibility**: Additional Node.js APIs where applicable
 
 ## Additional Resources