New public Ardor repository

Nxt and Ardor lead developer Jean-Luc (Jelurida) has announced that he will change the location of the official public Ardor repository from to

Ardor packages uploaded to the Jelurida repository will be signed with the
official Jelurida software releases signing key, 0xC654D7FCFF18FD55, already
used for signing the Private Blockchain Evaluation Kit packages.

The latest release 2.0.3e has already been uploaded to the new location.
In a few days, the old repository will be deleted, with a notice directing
users to the new one. Please update any hardcoded website links.


Ardor Testnet is Launched

Early this morning, Jean-Luc, lead core developer of Nxt and Ardor, made an announcement on about the launch of the Ardor testnet. While some testing was already done by some members of the Nxt community who were very knowledgeable about the platform, as we mentioned in our previous newsletter, much more testing is needed to be done before the launch of mainnet in the third quarter of this year, thus the release of testnet. Also, this is a great way to experience the Ardor blockchain without risking any funds as the tokens are given away freely to people who want to try it.

At the moment, only .zip and .exe files have been released, so Mac users will have to wait a bit. Riker, core developer of Nxt and Ardor, mentioned that a client for Mac will likely be released in version 2.0.1e. However, users of Linux operating systems as well as Windows (32 and 64 bit) can get started now. Installation is very similar to that of the Nxt client, with the notable exception of some Ardor graphics.

Ardor’s Decentralized Polling

Some activity has already been going on in just a few hours after launch. On the testnet Ignis child chain, a poll was started asking users about their favorite animal among the animals mentioned. You can take a look at this by choosing the Ignis child chain on the testnet client, clicking on “Voting System” and then “Active Polls”. Remember, while all transactions are processed by the main chain which takes ARDR, when you’re on a child chain all processing is paid for in the child chain token. So, Ignis tokens are required in order to cast your vote.

Sending Bitcoin Using the Alias Feature On Ardor

This is just one of the few things currently being tested at the moment. Get the testnet client and to find out how to request test tokens on today and experience this new blockchain platform. If you find any bugs, please report them over at Nxtforum on the announcement thread or through one of the channels listed on the website.

Ardor GUI screenshots

Damelon, of the Jelurida, has shared some previews with us regarding the Ardor platform.

This time a screenshot of the Coin Exchange, which allows users to exchange tokens in one child chain against tokens in another child chain, or against Ardor.

Here it is:

A preview of the dialog windows for bundlers has also been shared.

“Bundlers” will bundle child chain transactions and send them to the Ardor main chain where they will be “forged”. This operation costs ARDR. You can read more about how bundling will work in this newsletter.


Advanced Users of Nxt are testing Ardor

Riker, one of the Nxt and Ardor core developers, has invited users on NxtChat on Slack who have a solid knowledge of Nxt to test the new Ardor software on the testnet, in order to speed up the opening of the testnet to general users, which is expected to happen in the near future.

Lior says:

As we are wrapping up the Ardor testnet release, and before we release it publicly, we are looking for power users who know NXT 1.x well to join us in testing the platform. This would be a volunteer base work (unless some whale would like to put an NXT or Ardor bounty for this). You have to be very technical, not easily frustrated and if you have prior background in software development and testing that’s a big plus.

What you will get is:
Access to an Ardor testnet public node first, then access to a binary distribution, and the chance to work with folks like JL, myself and other core devs side by side, who knows, perhaps this would also develop into an employment opportunity in the future.

Most important is UI testing. API testing is important as well. We need someone to test processes like create a poll, vote, check the results. Create an asset, send multiple ask/bid orders and verify that the trade results are correct etc. No need for coding but if know how to place a breakpoint in JavaScript code and check some variables values that’s a big plus.

More information:

Channel #developers at Nxtchat on Slack

Ardor Features vs Nxt Features

Jean-Luc, Nxt and Ardor core developer, has published a chart on that compares the major differences in the functionalities between Nxt and Ardor:


Single chain One parent chain with multiple child chains

Transaction tokens

The same token (NXT) is used for establishing the consensus and providing the security of the blockchain, as well as for the basic unit of value in all transactions Only the parent chain token (ARDR) is used in the proof-of-stake consensus, and thus provides security for all child chains. Child chain tokens are used as transactional units of value only.

Transaction fees

Transaction fees are paid in NXT only, requiring users to always have NXT in their accounts. On each chain transaction fees are paid in the native token (coin) of that chain. End users do not need to own ARDR tokens.


Asset Exchange, Monetary System, Aliases, Messaging, Digital Goods Store, Voting System, Shuffling, Data Cloud, Phasing, Account Control, Account Properties All these features are preserved in Ardor, and are available on each child chain. A child chain can optionally be restricted not to enable some features. The parent chain supports a limited subset of features, as it is intended to be used for consensus establishing only and not for everyday transactions.


Each passphrase maps to a single account. Passphrases can’t be changed, and there is no wallet file to store. The same mapping of passphrases to account numbers is used as in Nxt. Accounts are global across all child chains, and an account can have balances in each of the existing child chain coins, as well as in ARDR.


There is a single coin (NXT), and unlimited user-issued Assets and Monetary System currencies. Each chain has its own coin. Assets and MS currencies can be issued on any child chain, and are available for trading globally. Assets or MS currencies can optionally be restricted* to some child chains only.


Assets and MS currencies can be traded for NXT only. Assets and MS currencies can be traded on any child chain, with price denominated in the corresponding child chain coin.

Coin Exchange

N/A A new feature, Coin Exchange, allows trading of child chain coins to each other, and also to the parent chain coin (ARDR).


Asset dividends can be paid in NXT only. Asset dividends can be paid in any of the child chain coins, by simply issuing the payment transaction on the corresponding chain. Additionally, paying dividends in another Asset or in MS currency has been implemented.


Crowdfunding feature is available in the Monetary System, but the funds must be collected in NXT only. Crowdfunding feature is available on all child chains, and on each child chain the funds are collected in the corresponding child chain coin.


Shuffling of NXT, Assets, and MS currencies is available. On each child chain, shuffling of the corresponding coin, or any Asset or MS Currency, is supported.


Alias names are globally unique. Alias names are unique within each child chain only.

MS Currencies

Currency codes and names are globally unique. Currency codes and names are unique within a child chain only.


Pruning is available for plain and encrypted messages, and for tagged data (data cloud feature). Pruned data are retrieved automatically on demand from designated archival nodes. Pruning and retrieving of all prunable data is available as in Nxt. In addition, the child chain transactions themselves are designed to be prunable and will not need to be stored permanently or re-downloaded by every new node. The actual pruning of transactions will be implemented later.*

Transaction identifiers

Transaction IDs are 64-bit longs, and are globally unique. The 64-bit transaction IDs are no longer guaranteed to be globally unique for child chains. 256-bit transaction hashes (sha256 digests) are used instead as transaction identifiers.

Block generation

A “forging” process is used to create new blocks, with the probability of block creation dependent on the account NXT balance (stake). The same forging algorithm is used as in Nxt, dependent on ARDR account balances only.


N/A A new process, “bundling”, is used to group child chain transactions into a parent chain transaction (“child chain block”), which is then included in the parent chain. Any account can play the role of a bundler. The bundling process also performs the exchange of fees paid by users in child chain tokens into ARDR fees accepted by the block forgers.


Transaction execution can be made conditional, subject to approval using various voting models. Same voting models as in Nxt, but phasing is possible on child chains only. Approval transactions can be on a different child chain from the phased transaction, and the by-transaction voting model also supports linking to a transaction hash on a different child chain.

Account control

Accounts can be restricted to use phasing only (mandatory approval). Same as in Nxt, but accounts under phasing-only restriction cannot submit transactions on the parent chain, as those cannot be phased.

Peer networking

HTTP based, also with WebSocket support, transmitting JSON formatted data between peers. Completely re-written and optimized, using native Java sockets and binary messages between peers. Block and transaction propagation has been significantly improved, by exchanging and caching information about currently available blocks and transactions between peers and only propagating the missing data pieces.


HTTP query APIs, returning JSON formatted response. Mostly unchanged, except:
1. A “chain” parameter has been added to each API that is child chain specific.
2. 64-bit long transaction IDs have been replaced with 256-bit hashes.
3. All prices and rates that were previously defined relative to the smallest indivisible holding amount (“QNT”) are now defined relative to a unit of the holding (share).


Transactions are stored in the blockchain permanently, and need to be re-downloaded and re-processed by every new node, which after months and years of operation becomes a significant bottleneck. All child chain transactions will be possible to prune completely, without affecting blockchain security, thus allowing the blockchain size to be kept much smaller. A new node joining the network only needs to download the parent chain transactions, followed by the latest snapshot of the current system state.*

* Functionallity marked with asterisk is planned to be implemented in a future Ardor release. All other functionallity is already implemented and currently being tested on a testnet blockchain.

Source and more information:

Ardor Testnet Countdown

Riker, Nxt and Ardor core developer, published a list of all the remaining tasks that have to be completed before the Ardor Testnet goes live. There isn’t an exact date when the the launch of the testnet will take place yet, but it will happen in this first quarter of 2017. It’s important to note that after some previous leaked images, the market capitalization of Nxt and Ardor went up, which shows how many people are keeping and eye on these projects. Obviously, there is a lot to be expected.

Lior writes:

Getting closer to the Ardor testnet release but still some way to go.The server code is nearly complete and the APIs are mostly stable… Most of the work will now focus on getting the client UI ready for release

Here is a list of remaining tasks which we would like to complete before the official release:
– More work on the Coin Exchange page and tables
– Prefix each MS currency name with the name of the chain to which it belongs – partially implemented
– Ability to link from a child chain transaction to the ChildChainBlock transaction in which it was bundled – done
– Improve the entity properties modal to support entities like orders and offers – done
– Format amounts and links in the entity properties modal
– Test and fix currency reserve/claim tables and modals
– Remove child chain specific widgets from the Ardor UI
– Reomve Ardor specific widgets from the child chain UI
– UI for the new “by holding” dividend modal
– UI for the “by holding” dividend history

Source and more information: