Is Selenium WebDriver compliant with W3C standards?

Yes, Selenium WebDriver is compliant with W3C standards. The Selenium project has worked to ensure that WebDriver follows the W3C WebDriver protocol, which is a standard that defines a web API for interacting with web browsers.

The W3C WebDriver standard provides a platform- and language-neutral wire protocol that allows out-of-process programs to remotely instruct the behavior of web browsers. This standard was created to enable interoperability of browser automation tools and to make web browser automation less dependent on the internal implementation details of each browser.

Selenium WebDriver is designed to provide a friendly API that can control a browser in a way that is compliant with the W3C standard. The transition to W3C WebDriver compliance means that Selenium interacts with browsers in a consistent and standardized way, which is beneficial for both browser vendors and users of Selenium.

Here is a simple example of using Selenium WebDriver in Python to open a browser and navigate to a web page, following W3C WebDriver standards:

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

# Set up the WebDriver (this example uses Chrome)
driver = webdriver.Chrome()

# Go to a website
driver.get("http://www.example.com")

# Close the browser
driver.quit()

In the case of JavaScript, using Selenium WebDriver might look like this:

const { Builder, By, Key, until } = require('selenium-webdriver');

(async function example() {
  let driver = await new Builder().forBrowser('chrome').build();
  try {
    // Go to a website
    await driver.get('http://www.example.com');

    // Perform some actions, for example, find an element or interact with the page
    // await driver.findElement(By.name('q')).sendKeys('webdriver', Key.RETURN);
    // await driver.wait(until.titleIs('webdriver - Google Search'), 1000);

  } finally {
    // Close the browser
    await driver.quit();
  }
})();

In these examples, the webdriver module in Python and the selenium-webdriver package in JavaScript are used to control a browser. Selenium sends commands to the browser driver (for Chrome, it's chromedriver; for Firefox, it's geckodriver, etc.), which in turn sends standardized W3C WebDriver protocol commands to the browser.

For the W3C WebDriver standard to be effectively implemented, the browser drivers themselves must also be compliant. Major browser drivers such as chromedriver, geckodriver, and MicrosoftWebDriver implement the W3C standard, thus enabling Selenium to interact with browsers in a standardized way.

When using Selenium WebDriver, it's important to ensure that the version of Selenium, the browser, and the browser driver you are using all support the W3C WebDriver protocol. More recent versions are more likely to be compliant, as the W3C WebDriver became an official W3C recommendation on June 5, 2018.