# Ciao

> programming language

**Wikidata**: [Q5119098](https://www.wikidata.org/wiki/Q5119098)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Ciao_(programming_language))  
**Source**: https://4ort.xyz/entity/ciao

## Summary
Ciao is a programming language that supports multiple paradigms including logic programming, constraint logic programming, and object-oriented programming. Influenced by Prolog, it is classified as both an object-based language and a constraint logic programming language. Ciao is open-source software released under the GNU General Public License.

## Key Facts
- **Instance of:** Programming language, constraint logic programming language, object-based language
- **License:** GNU General Public License
- **Influenced by:** Prolog
- **Programming paradigms:** Logic programming, object-oriented programming, constraint logic programming
- **Website:** http://www.ciao-lang.org
- **Source code repository:** https://github.com/ciao-lang/ciao
- **Latest stable version:** 1.20.0 (released April 4, 2021)
- **Previous versions:** 1.19.0 (March 21, 2020), 1.18.0 (December 19, 2018), 1.16 (July 14, 2018)
- **Wikipedia presence:** Available in English and Persian (fa)

## FAQs

### Q: What programming paradigms does Ciao support?
A: Ciao supports three main programming paradigms: logic programming, constraint logic programming, and object-oriented programming. This multi-paradigm approach allows developers to use different programming styles within the same language.

### Q: What license is Ciao released under?
A: Ciao is released under the GNU General Public License (GPL), making it free and open-source software. This allows users to study, modify, and distribute the language freely.

### Q: Is Ciao related to Prolog?
A: Yes, Ciao is influenced by Prolog, as documented in its development history. This influence is reflected in Ciao's logic programming foundations.

## Why It Matters
Ciao represents an important development in the evolution of logic programming languages. By combining multiple paradigms—logic programming, constraint logic programming, and object-oriented programming—into a single language, Ciao offers programmers flexibility in how they approach problem-solving. Its constraint logic programming capabilities enable it to handle complex computational problems where traditional imperative languages might struggle. The language's open-source nature under the GNU General Public License ensures accessibility for researchers, educators, and developers. Ciao's continued development, with releases as recent as 2021, demonstrates ongoing community engagement and maintenance, making it a viable option for modern programming needs in academic and research contexts.

## Notable For
- Multi-paradigm design combining logic, constraint, and object-oriented programming in one language
- Open-source availability under the GNU General Public License
- Active development with regular releases through 2021
- Foundation in Prolog while extending capabilities with constraint logic programming
- Object-based language features integrated with logic programming foundations

## Body

### Classification and Paradigms
Ciao is classified as a programming language, specifically categorized as both a constraint logic programming language and an object-based language. It supports three distinct programming paradigms:
- Logic programming
- Object-oriented programming
- Constraint logic programming

This combination allows Ciao to serve as a versatile tool for developers working across different computational approaches.

### Development History
Ciao has maintained an active release schedule in recent years:
- **Version 1.16:** Released July 14, 2018
- **Version 1.18.0:** Released December 19, 2018
- **Version 1.19.0:** Released March 21, 2020
- **Version 1.20.0:** Released April 4, 2021

The language is influenced by Prolog, indicating its roots in logic programming traditions.

### Licensing and Availability
Ciao is distributed under the GNU General Public License. The language is copyrighted but freely available for use, modification, and distribution under the terms of the GPL.

### Resources and Documentation
- **Official website:** http://www.ciao-lang.org
- **Source code repository:** Hosted on GitHub at https://github.com/ciao-lang/ciao
- **Wikipedia coverage:** Available in English and Persian (fa)

## References

1. [Release 1.16. 2018](https://github.com/ciao-lang/ciao/releases/tag/v1.16)
2. [Release 1.18.0. 2018](https://github.com/ciao-lang/ciao/releases/tag/v1.18.0)
3. [Release 1.19.0. 2020](https://github.com/ciao-lang/ciao/releases/tag/v1.19.0)
4. [Release 1.20.0. 2021](https://github.com/ciao-lang/ciao/releases/tag/v1.20.0)