> For the complete documentation index, see [llms.txt](https://cpb.gitbook.io/book/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cpb.gitbook.io/book/languages/haskell/misc.md).

# Some interesting facts

* [**Galois**](https://galois.com/) is an active Haskell user.
* **Facebook** uses Haskell in several projects, including [Fighting spam with Haskell](https://code.fb.com/security/fighting-spam-with-haskell/)
* **Ericsson** uses Haskell for the implementation of [Feldspar](http://hackage.haskell.org/package/feldspar-compiler), an EDSL for digital signal processing algorithms.
* **Kaspersky** uses Haskell in it's antivirus software

## Haskell code compared to other languages

> Example of Hello World code in several languages.

### Haskell

```haskell
module Main where

main :: IO ()
main = putStrLn "Hello, World!"
```

### Golang

```go
package main

import "fmt"

func main() {
    fmt.Println("Hello, World")
}
```

### Python

```python
print "Hello world!"
```

### Ruby

```ruby
puts "Hello world!"
```