tl;dr: Use Vim or Emacs. Really.

The traditional editor tools for Linux are Vim ^[1] and Emacs ^[2]. Don’t let their vintage text-only look scare you away – they are state-of-the-art editors. In fact, if you look at their feature sets they blow all other editors out of the water. They do, however, have a steep learning curve (but there’s unanimous agreement that it’s time well spent).

If you are serious about working with code, there is simply no replacement for either of those text editors. Incidentally, many people will argue that this is true even for other platforms.

That said, there are other tools. If you are willing to spent a little money, give Sublime Text ^[3] a shot. By all reports it’s a truly excellent editor.

Another free alternative is Geany ^[4] which describes itself as having “basic features of an IDE”.

Finally, if you’re not willing to learn the use of a new editor, give Notepad++ in Wine ^[5] a shot. According to reports it works quite well.

Historical note

This answer used to recommend gedit ^[6], and at the time of writing that was indeed a viable replacement for Notepad++. However, it seems like the development of that editor has slowed down to a crawl (see comments for details). Since this question gets lots of hits from search engines I’ve opted to update my answer since the old one was no longer useful.

Geany is pretty similar to Notepad++. Supports syntax highlighting for several languages, auto-indent, tabs, etc. While plenty of the other editors listed here are excellent, geany is the most similar to Notepad++.

I think Sublime Text ^[1] is the best editor out there for Linux. It's got regex search and very cool syntax highlighting and all the features n++ have and much more.

Notepad++ works well with Wine.

I vote for Geany, it is in Ubuntu repositories.

If you are using KDE, give kate ^[1] a try.

Notepad++ is ported to linux under the name Notepadqq ^[1]. It's being actively developed here ^[2].

GEdit is indeed more powerful than it may appear at first; in particular, the plugin system allows it to gain pretty much all the functionality you would find in something like Windows' Notepad++.

There are plenty of sites that give you tips on "tricking out" your gEdit, such as this one ^[1], or this one ^[2] or this one ^[3] for a more-or-less comprehensive listing. Googling around will find you many more.

Komodo edit ^[1] (large image if opened in new tab).
Non java (read: it's fast), free, has plugins, built around scintilla just like Notepad++.

There is also IDE (not free, but with debugger, version control etc).

I highly recommend SciTE:

http://www.scintilla.org/SciTEDownload.html

It is fast, light, highly configurable, and cross-platform. I've tried GEdit, Kate, NEdit, vim, etc., but SciTE gets my vote.

If you are looking for the same editing component, use SciTE. SciTE and Notepad++ both use Scintilla behind the scenes.

My personal favourite is currently Sublime:

http://www.sublimetext.com

It is, however, not free (although the trial is unlimited). Prior to that I used SciTE extensively (and before that nedit!).

As a LONG time user of notepad++ (about 16 hours a day for 5 years or so) I had a hard time switching to linux for the exact same reason the OP asked his question. This time when I switched to linux it happened to have Kate preinstalled (Linux Mint 12 KDE).

I must say that I have tried quite a few linux editors in the past looking for one that had many of the features I love ab out notepad++ out of the box, including double clicking a word and highlighting all instances or the word or variable, complex search functionality, line duplication by hotkey (ctrl+alt+up/down), moving lines up or down by hotkey(ctrl+shift+up/down), among others.

Kate has left me with no features to miss, and actually with some tweaking actually FEELS a lot like notepad++, and includes a handful of features that notepad++ had but felt quirky, but in Kate they do them right! This, along with file managers actually starting to support svn and git icon overlays, has allowed me to move to linux full time for development and home use.

So, to the OP, if you are looking to a good match to notepad++, go with kate, if you want a conversation about who prefers what editor on linux, ask your question differently. You will feel right at home pretty quickly, compared to other editors.

I will be checking out the komodo one the guy a few above me posted though haha,

I would personally recommend VIM or GVIM. Its features are unmatched as far as I am concerned. Code folding and syntax highlighting are key features that are in both applications.

after a long time of searching the best Notepad++ alternative in Linux, I find that Notepad++ is the best alternative for Notepad++ in Linux. :-)

Here is the solution:

1. Install Wine from Ubuntu software Center, I used Wine 1.1.31;
2. Download Notepad++Portable link text ^[1];
3. Go to your Notepad++ download folder, right click on the *.exe file and chose Open with Wine.....
4. Chose your language, chose your C:\Program Files\Notepad++Portable and click Install; 5 Go to Aplication Ubuntu menu, in Aplications/Wine/Browse c:/Drive or paste the following ~/.wine/dosdevices/c:/Program Files/Notepad++Portable in your File explorer
5. Right click on Notepad++Portable.exe and chose Open with Wine.....

A good editor that I've recently come across is Textadept, an open source editor which can be found at

http://foicica.com/textadept/

It uses the same Scintilla editing widget that SciTE and Notepad++ use. It is fast, powerful, and highly extensible. It is also not as unintuitive as vim or emacs (surprise, Ctrl+C and Ctrl+V actually do copy and paste). Like SciTE, it is extensible in Lua and has very good documentation about how to extend it. I was able to change around a lot of the key commands the first day I started using it.

It has a large number of community-developed extensions and an astounding quantity of supported languages. Both of these are testaments to the ease with which the program can be extended.

It's not in the Ubuntu repositories yet, but there are easy-to-install binary packages available on the project website.

You may like vim, with the plugins you want.

See:

http://www.vim.org/
http://www.vim.org/tips/index.php

http://www.vim.org/scripts/index.php
http://www.vim.org/scripts/script.php?script_id=1658

Welcome to the dark side :)

From the top of my head, I would suggest gVim, the "graphical" version of Vim. It's an extremely competent editor, but it takes some time to get used to it. I had to check the tutorial to understand all the shortcuts etc. It has syntax highlighting for most languages.

But i don't know of any good WYSIWYG editor. However, you could of course try to run Notepad++ through Wine ^[1]. That might work :)

Give Editra ^[1] a try. It is open source and written in Python (runs on most platforms). The code is pretty stable. The project is being actively developed. Editra was recently featured on lifehacker ^[2].

Full Disclosure: my friend and colleague started the project

There is another thread about it here, but jEdit is a Java-based editor which is in the Ubuntu repositories.

If you're used to Notepad++ it will probably have a slightly easier learning curve for you than Vim or Emacs, and I find it has more (useful) features than gEdit - and it has loads of plugins.

www.jedit.org, if you want the actual website :)

Try gedit and the gmate plugin (adds a collection of plugins and themes) for Textmate like functionality

http://www.webupd8.org/2010/12/get-textmate-features-and-styles-in.html

According to the site, there are 100 themes from textmate and a lot of plugins for web development.

Installation

sudo apt-add-repository ppa:ubuntu-on-rails/ppa
sudo apt-get update
sudo apt-get install gedit-gmate

Like others, I'd recommend running it under WINE, or if you just need to do some basic editing, like maybe adding a couple lines to your /etc/apt/sources.list, then you could try nano, which is run in the terminal. It's extremely easy to use, and gets the job done. It even has some basic syntax highliting, for example shell scripts. Tis isn't something you'd want to use for say hugely long C++ source editing, but for some shell scripts, or adding a few lines, it's very good. And, as a plus, it's kind of nice if your working in the terminal to stay in the terminal, rather than fumble around with another program. Just my two cents :)

I would simply use Notepad++ with wine. Its got too much stuff to give up.

You can install it in a few minutes!

http://bur.st/~gunny/winehowto.html

You could try gvim or xemacs, they'll probably take longer to get used to than np++ but either should be able to do everything you need. If this isn't good enough, you could also always just run np++ in Wine :)

I second vim/gvim. However, if you're looking to ease the transition to vim, you can use cream, which is kind of like vim w/ insert modes as default (there's probably more to it than that, though...)

http://cream.sourceforge.net/

Notepad++ works fantastically in Ubuntu under wine. If you absolutely can't do without it, you can still have it.

I personally have been using Medit because it's lightweight, although it doesn't have some of the best featured of notepad++. Specifically, the split screen view is something I miss almost every single day.

I like gEdit and I followed most of the tips that I found here ^[1] to make it a pretty good lightweight IDE.

Emacs has great support for all kinds of different editing modes and is still quite usable even for new users. It also allows for massive customization once you realize it's the best thing that ever happened to you.

you should really learn VIM... vi is in every linux and unix build ... therefore no matter what machine you get on, you will be able to do very powerful editing. emacs would be the other choice to learn... the other programs are nice but you will all thank us once you get passed the learning curve and your production will FLY... even if you use gvim/cream on windows it is WELL worth it. I have to use windows at work and people come by and see me running vim and are like WTF is that! meanwhile they use shitty dreamweaver lmao

Notepad++ under wine is OK but why? syntax highlighting is broken and some other things in it are broken like pop up boxes that take an integer. so it is pointless. Great app in windows though.

Kate is fantastic alternative. The fonts are very smoothed (antialiased), it's reasonably snappy and has a lot of great features that are useful in notepad++ like being able to see all characters, change line endings, syntax highlighting, line numbers, code folding i believe, etc.

I would not recommend gvim or emacs. It's 30 years into the future for them, folks, we don't need to hamhand our keyboard with tekkenlike combos because of the advent of the mouse and simple cut paste, home, end keys and a modest number of combos. Plus, it's a total pain in the butt to get emacs fonts to NOT give everyone a severe tension headache after looking at the horrible fonts for 5 minutes. Yes i know there's a way to fix this, but it's unclear, badly documented and unless you are some ubergeek you are just goign to waste hourse of your life getting emacs to work half=as well as ultraedit, which is now native to linux but unfrotunately not free.

Emacs and Vi are you best options, the power of those will dwarf anything that notepad++ can do...The learning curve is steep.

Gedit is pretty good with a few add-ons.

gedit has long been a staple of my X installations. GVim is handy as well, but with Gedit and vi, I have just about everything I want.

Gedit if you're using Gnome, or KWrite if you're using KDE, or Mousepad if you're using XFCE (although I don't know if it has syntax highlighting).

Notepad++ will run under Wine.

I like vim (use it even on Windows) but if you want to avoid the steep learning curve and use something more "Windowsish", try NEdit: http://www.nedit.org/

Cream ^[1] will give you the power of Vim with the convenience of a graphical interface.

There are lots of plugins that you can add to the "base" editors of the main linux frontends Gedit (for Gnome), KWrite (for KDE) or MousePad (for XFCE), but if you want something more equipped from the beginning try Geany (for Gnome or XFCE) or Kate (for KDE).

I found MadEdit quite an ok replacement, though mind you, it's on my university's computers, so I have no idea where to get it from.

Although Notepad++ is a good editor, I find it quite slow when working with large files (>5MB) even when browsing in the file. That's why I moved to a paid solution, Editplus (which is really fast).

For Ubuntu I have problems with Gedit when working with large file (20MB MySQL database dump), it closes without notice after a search&replace operation in the whole file. It's a nasty bug.

I moved to Kate and Geany, they are both fast and have lots of features.

My move to Ubuntu was hard. I missed Notepadd++ and also Dreamweaver. Now im working with "geany" If you are missing the "highlighting similar words function" => Just select the word and click "Strg-Shift and M"