These sources collectively explore the cutting-edge developments in artificial intelligence, focusing on two prominent AI models: OpenAI's GPT-5 and xAI's Grok 4. One source provides an overview of the history and philosophical differences between OpenAI co-founder Sam Altman and xAI founder Elon Musk, highlighting their past collaboration and subsequent divergence regarding AI's direction. The remaining sources offer detailed comparisons and analyses of GPT-5 and Grok 4, discussing their performance on various benchmarks, architectural advancements, and practical applications, as well as community impressions and future development plans for each model.