GPT-5.3 Codex vs Claude Opus 4.6: Which AI Coding Assistant Is Better in 2026?

If you are a new developer, you have probably hit the “subscription wall.” You have $20 a month to spend on an AI coding assistant, but you don’t know which one to pick.

If you are a new developer, you have probably hit the “subscription wall.” You have $20 a month to spend on an AI coding assistant, but you don’t know which one to pick.

The Mandelbrot set. And it's a program! I made it in g++, a freely distributable C++ compiler. Read it! Very interesting. Using OpenMP, you do parallel programming at the multithreading level. And I decided - this would be a completely different level of quality! I implemented honest supersampling (antialiasing) - with 8x8 antialiasing (64 passes per pixel!!!) That is, not 1920 by 1080 pixels, but 8x8 more! 15360 by 8640 pixels! And then these 64 passes reduce by one pixel, but smoothly - and no longer 8-bit, but 24-bit TrueColor!

A utility for supporting Xray on Keenetic routers — Xkeen.
All the code is written in pure shell and is open source on GitHub.
Builds Xray for your Keenetic on Entware.
GeoIP and GeoSite from AntiFilter, AntiZapret, and v2fly are available.
Automatically updates Xray, GeoIP, and GeoSite at a specified time.

What is a sequence diagram? What does it consist of? Where and how to use it?
Sequence diagrams in simple terms.
And there are also interesting features here that you might not have known about.

The Chinese neural network DeepSeek has recently gained popularity. Today, we'll figure out how to work with its API, how to pay for it from Russia, and whether there are any difficulties.

A Telegram Mini App is a web application built into the messenger that allows users to access a service without installing separate programs. This allows for a convenient service integrated with the messenger's ecosystem, whether it's an online store, a booking system, etc.
We have written a general overview of this application, its capabilities, the first steps to creating one, and existing examples.

I finally decided to replace my old Linksys router and buy a new gigabit router with a built-in VPN – that's what most retailers call the feature, without specifying whether they mean a VPN client or a VPN server.
After some searching, I managed to find only one major seller – the orange one with three letters – whose website has advanced filtering for routers by VPN parameters, such as protocol and operating mode (client/server).
And so, with a list of several dozen candidates for purchase, the main question arose – what speed over VPN can each of them deliver?

In this article, we will look at how you can customize Windows, adjusting the appearance and functionality of the operating system to your preferences. This can be done using both built-in tools and third-party programs.
When customizing Windows, it's important to remember that most third-party programs make changes to system files and the registry. This can lead to malfunctions, conflicts between utilities, and problems after operating system updates.
List of utilities that will be covered in this article: PowerToys, WinAero Tweaker, ExplorerPatcher, Rainmeter, TranslucentTB, EarTrumpet.
By the way, if you are interested in IT technologies and useful tools, check out my Telegram channel. I regularly post fresh news, life hacks, and other useful things there. And now, to the heart of the article.

A categorical welcome to everyone. Literally on the first of August, right in the middle of the night, YouTube started lagging terribly for me. Naturally, I didn't like this at all. Well then, let's figure out why and how to fix it within my personal network.
What happened?
What happened is well described here, on Habr. In short, in my own words - during the SSL connection setup, the domain we are connecting to (the so-called SNI) is transmitted in plain text. And if it's googlevideo.com, then "interesting things" start to happen. You can check this locally with the commands from the article.
$ curl https://speedtest.selectel.ru/100MB -o/dev/null
Image generation by neural networks has become a 'regular button' alongside familiar design tools. Today, you can create an image from a description in Russian, right in your browser, often without registration and, importantly, for free. Such a 'free image generator' is useful not only for designers: entrepreneurs create product cards and hero banners, SMM specialists create ad creatives and stories, journalists and bloggers create illustrations for their materials, and developers create interface prototypes and game mockups.
Why has this topic become so popular?

A brief and clear description of the RAG (Retrieval Augmented Generation) approach for working with large language models.
Hello, Habr!
Today we'll look at how to install the network packet modification utility Zapret on Keenetic routers. Unlike using it on specific devices, installing it on a router allows you to process traffic from all devices connected to your home local network (PCs, smartphones, and smart TVs).

> As of April 10, 2024, > three months later, > this article has been blocked by Roskomnadzor (RKN) > within the territory of the Russian Federation. > It has also been removed from the web archive archive.org. > The article on Habr remains accessible from IP addresses in other countries. > Yes, now to read about VPNs, you need a VPN.
Against the backdrop of last year’s escalation of censorship in Russia, the articles by MiraclePTR were a breath of freedom for many Russian-speaking IT folks. I want to open the door to free information a bit wider and invite “non-techies” (“dummies”) who want to spin up a personal proxy server to bypass censorship but feel lost in the flood of information or got stopped by a confusing technical error.
In this article I’ve described a universal solution that provides transparent access to the global internet bypassing censorship, uses cutting-edge traffic obfuscation, doesn’t depend on the will of a single corporation, and most importantly has ample ���safety margin” against interference from censors.
This article is aimed at “dummies” unfamiliar with the subject area. However, people “in the know” may also find something useful (for example, a slightly simpler setup for proxying via CloudFlare without having to run nginx on a VPS).
If you still don’t have a personal proxy to bypass censorship—this is your sign.

AI app builders have become very good at generating interfaces. From a technical perspective, that part is mostly solved. The harder problem is what comes next: connecting real data, enforcing user permissions, handling workflows, and deploying the app after the generation.

I constantly have multiple Chrome windows open, each with a pile of tabs. One window has a dozen slow analytics queries that I'll check "any minute now." Another has my research on $lookup and $unwind in MongoDB. The third one — with the most tabs — has local school enrollment rules, because life.
Tab-saving extensions have existed for ages, but reviews regularly complain about data loss — so why not build my own, designed specifically for backup? Every Chrome user already has a Google account, usually with sync enabled.
Here's how I used it to make Tab Saver extension that backs up to your Google Account without any signups and with zero configuration needed. It's pretty straightforward - you can easily use it as well.

Much attention is currently focused on the size of neural networks and the gigawatts of power consumed by data centers. However, the future lies not only in giant clusters but also in tiny chips embedded directly into the sensing elements of hardware. When a neural network is placed directly inside a sensor chip, it must be exceptionally efficient.
Through experimentation, I have successfully built a neural network architecture with 380 parameters (with potential for further reduction), capable of operating in conditions considered unsuitable for conventional algorithms.

This guide covers how to set up OpenClaw (formerly Clawdbot) on your local machine and, most importantly, how to secure it so strangers can’t access your computer. If you are ready, then let’s get started! :)

It’s surprising that there’s almost no practical information about Telegram Cocoon beyond what’s on GitHub and the official website. Various media outlets have plenty of general coverage about the network launch, but almost nothing about real user experience.
I decided to spend a bit of time and figure out what’s actually going on in the network, how it works, and, most importantly, whether I, as a developer, can use it today. So in this article I’ll look at Cocoon from a developer’s perspective: how to install it and how to use it.

Привет, Хабр! Меня зовут Юра Петров, я руководитель отдела разработки компании Friflex и автор канала «Мобильный разработчик». OpenAI на днях выпустила крутую статью, где впервые подробно описала работу своего агента для написания и изменения кода — Codex CLI. Сердце системы — «агентский цикл» (agent loop).
Это процесс, в котором модель получает задачу от пользователя, при необходимости вызывает инструменты (например, запускает команды в терминале), анализирует результат и повторяет цикл, пока не получит финальный ответ или не внесет нужные изменения в код. Статья фокусируется на том, как устроен этот цикл, как формируются запросы к модели и как система управляет контекстом.

Asynchronous I/O, ML-based query plan optimization, and built-in connection pooling are among the key features of the new Postgres Pro Enterprise 18. This release brings together the capabilities of the vanilla PostgreSQL 18 core with Enterprise-grade tools for working with large-scale data. Today we will walk through the technical details, new index scanning strategies, and mechanisms for scaling write workloads.
