About Me

Hi! My name is Nikita Popov, but you’ll mostly meet me as nikic on the internet. I’m a senior software engineer at Red Hat, working on LLVM, Clang and Rust.

Before that, I worked at JetBrains as a core developer for the PHP project. I studied computer science and physics at the Technical University of Berlin.

Feel free to contact me via nikic@php.net. Alternatively you can usually find me on the LLVM Discord.

Projects

My most popular open-source projects, sorted by stars:

• PHP-Parser – A PHP parser written in PHP
• FastRoute – Fast request router for PHP
• scalar_objects – Extension that adds support for method calls on primitive types in PHP
• iter – Iteration primitives using generators
• php-ast – Extension exposing PHP 7 abstract syntax tree
• PHP-Fuzzer – A fuzzer for PHP libraries

I also maintain the LLVM compile-time tracker.

Accepted PHP proposals

PHP 8.2:

• Deprecate dynamic properties
• Deprecate partially supported callables

PHP 8.1:

• Readonly properties
• First-class callable syntax
• New in initializers
• Array unpacking with string keys
• Deprecate passing null to non-nullable arguments of internal functions
• Static variables in inherited methods
• Restrict $GLOBALS usage
• Phasing out Serializable
• Deprecations for PHP 8.1

PHP 8.0:

• Union types
• Constructor property promotion
• Named arguments
• Reclassify engine warnings
• Consistent type errors for internal functions
• Always generate fatal error for incompatible method signature
• Stricter type checks for arithmetic/bitwise operators
• Validation for abstract trait methods
• Allow trailing comma in parameter list
• Object-based token_get_all() alternative
• Allow ::class on objects
• Static return type
• Variable syntax tweaks
• Weak maps
• Treat namespaced names as single token
• Saner string to number comparison
• Make sorting stable

PHP 7.4:

• Typed properties
• Arrow functions
• Allow throwing exceptions from __toString()
• Reflection for references
• New custom object serialization mechanism
• Deprecations for PHP 7.4
• Deprecate left-associative ternary operator

PHP 7.3:

• Deprecations for PHP 7.3
• Deprecate and Remove Case-Insensitive Constants

PHP 7.2:

• Deprecations for PHP 7.2

PHP 7.1:

• Forbid dynamic calls to scope introspection functions

PHP 7.0:

• Exceptions in the engine
• Abstract syntax tree
• Uniform variable syntax
• Remove deprecated functionality in PHP 7
• Reclassify E_STRICT errors
• Remove alternative PHP tags
• Remove hexadecimal numeric strings

PHP 5.6:

• Variadic functions
• Argument unpacking
• Operator overloading for GMP

PHP 5.5:

• Generators and coroutines
• empty() on arbitrary expressions
• Remove /e modifier from preg_replace()
• Support non-scalar foreach keys

Presentations

• PHP 7: What changed internally? [IPC’15]
  (slides)
• PHP 7: What changed internally? [PHP Barcelona’15]
  (slides, video)
• PHP 7: What changed internally? [Forum PHP’15]
  (slides, video)
• PHP language trivia [PHPKonf’17]
  (slides)
• Static Optimization of PHP bytecode [PHPSC’17]
  (slides)
• Static Optimization of PHP bytecode [phpDay’17]
  (video)
• Typed Properties and more: What’s coming in PHP 7.4? [PHP Russia’19]
  (slides, video)
• PHP performance trivia [PHP Barcelona’19]
  (slides, video)
• Looking forward to PHP 8 [PHPKonf’19]
  (slides, video)
• What’s new in PHP 8.0? [PHP fwdays’20]
  (slides, video)
• What’s new in PHP 8.0? [PHPConChina’20]
  (slides)
• Just-In-Time Compiler in PHP 8 [betterCode PHP’20]
  (slides)
• What’s new in PHP 8.0? [SymfonyWorld’20]
  (slides)
• Opaque pointers are coming [LLVM CGO’22]
  (slides, video)
• A whirlwind tour of the LLVM optimizer [EuroLLVM’23]
  (slides, video)
• Rust ❤️ LLVM [LLVM developer meeting’24]
  (slides, video)
• LLVM IR: Past, Present and Future [EuroLLVM’25]
  (slides)

Theses and Papers

• Spinor formulation of Lanczos potentials in Riemannian Geometry [Bachelor Physics]
  (pdf)
• Optimizing PHP Bytecode using Type-Inferred SSA Form [Bachelor CS]
  (pdf)
• The Tradeoff of Latency, Reliability and Rate for Spinal Codes [Master CS]
  (pdf)
• Static Optimization of PHP 7 [CC’17]
  (pdf, acm)

Miscellaneous

• PHP internals book
  Free (but incomplete) book on PHP extension development